Meaning

noun earnest and conscientious activity intended to do or accomplish something

noun use of physical or mental energy; hard work

noun a notable achievement

originFrom Middle French effort, from Old French esfort, deverbal of esforcier (“to force, exert”), from Vulgar Latin *exfortiō, from Latin ex + fortis (“strong”). Compare typologically Bulgarian усилие (usilie), Czech úsilí, Polish wysiłek, Russian уси́лие (usílije) (< Proto-Slavic *sila).

Etymology from Wiktionary, CC BY-SA 3.0