Answer:
A vestigial trait (i.e. organ, appendage, etc) is a remnant part of an organism that historically was very important but evolutionarily is no longer needed. For example, the tailbone on humans is considered vestigial because it serves little to no purpose, although at one point it most likely connected to a tail.
Another example is the dew claw on a dog (the small, dangling claw on a dog's front paws). Clearly there's no use for it today, but at one point it may have served an important purpose for survival.
appendix
wisdom teeth
tailbone
male nipples xD
body hair
thymus gland
the "tip" of your ear
ear muscles