Definitions

1. adjective

Relating to or resembling a vestige, especially a small or traceable remnant of a past structure, organ, or function that has lost its original significance or usefulness.

“The vestigial wings of the flying squirrel are a remnant of its flying ancestors.”

2. noun

A vestige or a small remnant of a past structure, organ, or function.

“The vestigial organ in the human body is a small, non-functional remnant of a past evolutionary trait.”