memento

The word 'memento' entered English in the late Middle Ages, directly from the Latin word 'memento', which is a command meaning "remember!" This Latin form originated as a contraction of an older phrase, rooted in the Proto-Indo-European base men-, meaning "to think". In Christian liturgical Latin, the phrase "Memento mori" ("Remember you must die") was used, and objects like skulls that symbolized this reminder were called 'mementos'. Over time, the word's meaning broadened from a solemn reminder of mortality to any object kept as a souvenir or reminder of a past event or person, preserving the core idea of prompting memory.

This word is a loanword from Latin, borrowed as a complete lexical unit. It is the imperative form of the Latin verb meminisse (to remember), meaning "remember!" or "be mindful of!".