a trace or visible sign left by something that has vanished or been lost; a minute remaining amount
a minute amount
a small or imperfectly formed body part or organ that remains from one more fully developed in an earlier stage of the individual, in a past generation, or in closely related forms
vestigial /veʹstij(y)əl/ adj
vestigially /vəʹstij(y)əli/ adv
[French vestige from Latin vestigium footstep, footprint, track]