vestigial

definition: 
(Of an organ or part of the body) degenerate, rudimentary, or atrophied, having become functionless in the course of evolution:
sentence: 
The belief that wisdom teeth are vestigial organs that lack a function in the body (as was previously believed for the appendix), is less common today but still evident.
difficulty: 
medium
toefl frequency: 
1
toefl classification: