1. A reminder of death or mortality, especially a death's-head.
2. A reminder of human failures or errors.

[New Latin mementō morī, be mindful of dying : Latin mementō, sing. imperative of meminisse, to remember + Latin morī, to die.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.