Although it has been said that "etymologists are unlikely to come to an agreement about the origins of 'cunt' any time soon," the word is most often thought to have derived from a Germanic word (Proto-Germanic *kuntō, stem *kuntōn-), which appeared as kunta in Old Norse. Scholars are uncertain of the origin of the Proto-Germanic form itself. In Middle English, it appeared with many spellings, such as coynte,cunte and queynte, which did not always reflect the actual pronunciation of the word. There are cognates in most Germanic languages, such as the Swedish, Faroese and Nynorsk kunta; West Frisian and Middle Low German kunte; Middle Dutch conte; Dutch kut; Middle Low German kutte; Middle High German kotze (prostitute); German kott, and perhaps Old English cot. The etymology of the Proto-Germanicterm is disputed. It may have arisen by Grimm's law operating on the Proto-Indo-European root *gen/gon 'create, become' seen in gonads, genital, gamete, genetics, gene, or the Proto-Indo-European root *gʷneH₂/guneH₂ 'woman' (Greek gunê, seen in gynaecology). Relationships to similar-sounding words such as the Latin cunnus (vulva), and its derivatives French con, Spanish coño, and Portuguese cona, or in Persian kun,Persian:کون, have not been conclusively demonstrated. Other Latin words related to cunnus are cuneus 'wedge' and its derivative cunēre'to fasten with a wedge', (figurative) "to squeeze in", leading to English words such as cuneiform (wedge-shaped).

The word in its modern meaning is attested in Middle English. Proverbs of Hendyng, a manuscript from some time before 1325, includes the advice:

Ȝeue þi cunte to cunnig and craue affetir wedding.
(Give your cunt wisely and make (your) demands after the wedding.)