The story
- Proto-Indo-European*méh₂tēr
- Proto-Germanic*mōdēr
- Proto-West Germanic*mōder
- Old Englishmōdor
- Middle Englishmoder
- Englishmother
- Proto-Indo-European*pewǵ-
- Proto-Germanic*fukkōną
- Old English*fuccian
- Middle English*fukken
- Englishfuck
- Englishfucker
- English todaymotherfucker
Compound of mother + fucker; attested since 1918. The injury comes from the implication of somebody sleeping with their own mother, but was probably not used literally until later. Also analyzed as a calque of Hindustani مَادَر چود (mādar cod) / मादरचोद (mādarcod).
Etymology from Wiktionary, CC BY-SA 4.0.