invertebrate

definition: 
An animal lacking a backbone, such as an arthropod, mollusk, annelid, coelenterate, etc. The invertebrates constitute an artificial division of the animal kingdom, comprising 95 percent of animal species and about 30 different phyla
sentence: 
During the breeding season they eat mostly insects and other invertebrates.
difficulty: 
medium
toefl frequency: 
1
toefl classification: