*1 : evenness of mind especially under stress
2 : right disposition : balance
Carol's famous equanimity didn't desert her, even in the midst of the crisis.
Did you know?
If you think "equanimity" looks like it has something to do with "equal," you've guessed correctly. Both "equanimity" and "equal" are derived from "aequus," a Latin adjective meaning "level" or "equal." "Equanimity" comes from the combination of "aequus" and "animus" ("soul" or "mind") in the Latin phrase "aequo animo," which means "with even mind."
English speakers began using "equanimity" early in the 17th century with the now obsolete sense "fairness or justness of judgment," which was in keeping with the meaning of the Latin phrase.
Equanimity quickly came to suggest keeping a cool head under any sort of pressure, not merely when presented with a problem, and eventually it developed an extended sense for general balance and harmony.
*Indicates the sense illustrated in the example sentence.