Meaning

noun the sum of money that is misappropriated

noun the fraudulent appropriation of funds or property entrusted to your care but actually owned by someone else

originLate 15th century, from Medieval Latin dēfalcātiōnem, accusative singular of dēfalcātiō (literally “cutting off, lopping off with a sickle”), nominalization of dēfalcō, from Latin dē (“off”) + falx (“sickle, scythe, pruning hook”), from which also English falcate (“sickle-shaped”). By surface analysis, defalcate + -ion (“the act of”).

Etymology from Wiktionary, CC BY-SA 3.0