Vestige • noun

  1. Trace of something that is disappearing or no longer exists
  2. Tiny often physical indication of something lost or vanished
  3. Smallest amount (used to emphasize the absence of something)
  4. Part or organ of an organism that has become reduced or functionless in the course of evolution

Fragment, trace, mark, print, imprint, impression, evidence, legacy,
echo, ghost, relic, shadow, trace

Related words:
memento, remembrance, reminder
artifact, afterimage, aftertaste
balance, corpse, hangover, leftover, oddment
remainder, remnant, scrap
dreg(s), leavings, remain(s), residual, residue, rest