The story
From Cantonese 師傅／师傅 (si1 fu6-2, “master”) and 師父／师父 (si1 fu6-2, “my master”), both also conveying the sense of teacher.
Etymology from Wiktionary, CC BY-SA 4.0.
sifu
Today it means: A master or teacher in the context of martial arts, especially kung fu and tai chi. Full definition →