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1 ubiquitous keyboard_arrow_downkeyboard_arrow_up
/ubiq-ui-tous/ [y.uw0.b.ih1.k.w.ih0.t.ah0.s]

The adjective "ubiquitous" describes something seeming to be seen everywhere.For example: 

  • Sugar is ubiquitous in the diet.
  • In the U.S., the camcorder has become ubiquitous.
  • Coffee shops are ubiquitous these days.
  • The wi-fi in Korea is ubiquitous.
  • Smartphones have become globally ubiquitous.
  • Fast food has become ubiquitous in the American diet, with over 25% of Americans eating fast food two or more times a week.


2 ultraviolet keyboard_arrow_downkeyboard_arrow_up
/ul-tra-vi-o-let/ [ah2.l.t.r.ah0.v.ay1.ah0.l.ih0.t]

Definition: (Of electromagnetic radiation) having a wavelength shorter than that of the violet end of the visible spectrum but longer than that of X-rays

Example sentences:

  • Most medical lasers emit light which are either ultraviolet, infrared or in the visible spectrum of light.

3 unanimously keyboard_arrow_downkeyboard_arrow_up
/unan-i-mous-ly/ [y.uw0.n.ae1.n.ah0.m.ah0.s.l.iy0]

Definition: Without opposition; with the agreement of all people involved

Example sentences:

  • The Board of Governors voted unanimously to allow the administrators to unionize. A committee of MPs has unanimously agreed to back his bill.

4 unconscious keyboard_arrow_downkeyboard_arrow_up
/un-con-scious/ []

Definition: Not awake and aware of and responding to one’s environment

Example sentences:

  • The boy was beaten unconscious.

5 underestimate keyboard_arrow_downkeyboard_arrow_up
/un-der-es-ti-mate/ [ah1.n.d.er0.eh1.s.t.ah0.m.ey2.t]

To underestimate is to guess that something is worth less or is smaller than it really is. 

Example sentences include:

  • The city underestimated the cost of the new building.
  • The number of people in the crowd was underestimated by 5,000.

The word “underestimate” can also mean to think of (someone or something) as being lower in ability, influence, or value than that person or thing actually is.

Example sentences include:

  • Never underestimate the importance of a good education.
  • Her talent has always been underestimated.

Please note that the overestimate is the opposite of underestimate.


6 underline keyboard_arrow_downkeyboard_arrow_up
/un-der-line/ [ah1.n.d.er0.l.ay2.n]

Used as a verb, “underline” means to give extra weight to, or extra importance. Used in a sentence, “What is the underlying issue here?” Meaning what is the most important issue.

7 unearth keyboard_arrow_downkeyboard_arrow_up
/un-earth/ []

To unearth something is to recover it by digging. Anything that is found my digging is unearthed, it could be a spoon or a body.  An example in a sentence:

  • The children were frightened when a skeleton was unearthed in our neighborhood.


8 uninhabitable keyboard_arrow_downkeyboard_arrow_up
/un-in-hab-it-able/ [ah2.n.ih0.n.hh.ae1.b.ah0.t.ah0.b.ah0.l]

An inhabitable place is a place that is suitable to live in. An example in a sentence:

  •  As our Sun gets older, it will get larger and warmer, eventually leading to the Earth becoming inhabitable.

An uninhabitable place is a place that is not suitable to live in. An example in a sentence:

  • If there's no roof then the house is uninhabitable.            
9 unmanned keyboard_arrow_downkeyboard_arrow_up
/un-manned/ [ah0.n.m.ae1.n.d]

Definition: Not having or needing a crew or staff:

Example senences:

  • Baxter's book was fiction, but we're seeing the same trade-off now in NASA's decision to cancel further unmanned missions and bring down the Hubble space telescope in order to spend more money on manned spaceflight development.


10 unsatisfactory keyboard_arrow_downkeyboard_arrow_up
/un-sat-is-fac-to-ry/ [ah2.n.s.ah0.t.ih0.s.f.ae1.k.t.er0.iy0]

Definition: Unacceptable because poor or not good enough:

Example sentences:

  • Teaching in a third of lessons was graded unsatisfactory or poor, while learning in two fifths of lessons was below standard

11 upheaval keyboard_arrow_downkeyboard_arrow_up
/up-heaval/ [ah0.p.hh.iy1.v.ah0.l]

An upheaval is a violent disturbance. It can mean a violent or disturbing change.

  • The French Revolution was a period of social and political upheaval in France from 1789 to 1799.​
  • There was an upheaval at the previous soccer game, so security was tightened for the rest of the season.


12 uranium keyboard_arrow_downkeyboard_arrow_up
/ura-ni-um/ [y.er0.ey1.n.iy0.ah0.m]

Definition: The chemical element of atomic number 92, a gray, dense radioactive metal used as a fuel in nuclear reactors. (Symbol: U)

Example sentences:

  • It is not certain if the effects are due to the chemical or the radioactive properties of uranium.

13 usher keyboard_arrow_downkeyboard_arrow_up
/ush-er/ []

To usher is to help find a way. Normally, people who lead you to your seats at a concert or movie theatre are called ushers. But certain ideas can also usher new ideas into place. Used in a sentence:

  • This idea encouraged trade which helped usher in the Renaissance

14 ubiquity keyboard_arrow_downkeyboard_arrow_up
/ubiq-ui-ty/ [y.uw0.b.ih1.k.w.ih0.t.iy0]

Ubiquity is the state of being everywhere all the time. Like a pop song that plays every place you go, or the ubiquity of mosquitoes in the summer or pollen in the spring. 

Example sentences:

  • With the ubiquity of the Internet, we are almost constantly connected to large amounts of information.
  • The iPod's ubiquity and the migration of most music online permanently altered our listening habits.
  • The ubiquity of the mosquitoes makes camping unbearable.
15 unaccountable keyboard_arrow_downkeyboard_arrow_up
/un-ac-count-able/ [ah2.n.ah0.k.aw1.n.t.ah0.b.ah0.l]

If you describe a person or organization as unaccountable, you are critical of them because they are not responsible to anyone for their actions, or do not feel they have to explain their actions to anyone.  People, especially those in leadership positions, are described as unaccountable when they behave as though they don't need to explain themselves, answer to anyone else, or take responsibility for their actions.

We can also use "unaccountable" to describe something that does not seem to have any sensible explanation. For example:

  • Crop circles, Big Foot sightings, and unidentified flying objects are mysterious and unaccountable.


16 unbiased keyboard_arrow_downkeyboard_arrow_up
/un-bi-ased/ [ah2.n.b.ay1.ah0.s.t]

Definition: with no preconceptions

Example sentences:

  • Even when business leaders do everything they can to ensure that their data are accurate and unbiased, errors can still occur.
  • He's proud to be a political scientist, one who takes seriously his responsibility to offer unbiased analysis.

17 undeniable keyboard_arrow_downkeyboard_arrow_up
/un-de-ni-able/ [ah2.n.d.ih0.n.ay1.ah0.b.ah0.l]

Definition: Unable to be denied or disputed:

Example sentences:

  • it is an undeniable fact that some dogs are easier to train than others

18 underlie keyboard_arrow_downkeyboard_arrow_up
/un-der-lie/ [ah2.n.d.er0.l.ay1]

Definition: (Especially of a layer of rock or soil) lie or be situated under (something):

Example senences:

  • Steep slopes underlain by stony soils form appealing vineyard sites, but they can be susceptible to rapid soil erosion during storms. Limestone underlies much of the site.

19 underway keyboard_arrow_downkeyboard_arrow_up
/un-der-way/ [ah2.n.d.er0.w.ey1]

Definition: Having started and in progress; being done or carried out

Example sentences:

  • It feels great to get under a hot shower and snuggle in my cozy cabin as the large vessel gets underway

20 unearthly keyboard_arrow_downkeyboard_arrow_up
/un-earth-ly/ []

Definition: Unnatural or mysterious, especially in a disturbing way:

Example sentences:

  • There was something strange in that moment when she looked at him, something unearthly and mysterious.

21 unlikely keyboard_arrow_downkeyboard_arrow_up
/un-like-ly/ [ah0.n.l.ay1.k.l.iy0]

Definition: not probable

Example sentences:

  • Bears are only relocated if they are in a situation where escape is unlikely or if public safety is threatened.

22 unprecedented keyboard_arrow_downkeyboard_arrow_up
/un-prece-dent-ed/ [ah0.n.p.r.eh1.s.ih0.d.eh2.n.t.ih0.d]

Definition: Never done or known before

Example senences:

  • The government took the unprecedented step of releasing confidential correspondence


23 unwarranted keyboard_arrow_downkeyboard_arrow_up
/un-war-rant-ed/ [ah0.n.w.ao1.r.ah0.n.t.ih0.d]

Definition: without a good reason or cause; inappropriate

Example sentences:

  • The assumption that a single gene is causative can lead to unwarranted conclusions and an over- interpretation of any genuine genetic linkage.
  • In the credit card industry, there are 1,000 rules regarding the use of so-called firewalls that block unwarranted access to sensitive information.

24 upheld keyboard_arrow_downkeyboard_arrow_up
/up-held/ [ah0.p.hh.eh1.l.d]

Definition: Confirm or support (something that has been questioned):

Example sentences:

  • The release of the film could be halted if a plagiarism claim is upheld by a High Court judge next week.

25 urbanity keyboard_arrow_downkeyboard_arrow_up
/ur-ban-i-ty/ [no ipa available]

Urbanites refer to people who live in the city, compared to the country or rural areas. Notice the base word “urban”, which should help you remember the meaning.