twelvetwelve

Twelve comes from Middle English twelve, from Old English twelf, from Proto-Germanic *twalif, a compound of *twai ‘two’ and *-lif ‘left over’.

1. Proto-Germanicc. 500 BCE–200 CE*twalif¹‘twelve’reconstructed
2. Old Englishc. 450–1150twelf¹‘twelve’
3. Middle Englishc. 1150–1500twelve¹
4. Englishearliest quotation 1972twelve¹

1. ¹ Wiktionary, English twelve
2. Earliest quotation in Wiktionary’s entry: 1972, Eleanor Webster Bulatkin, Structural Arithmetic Metaphor in the Oxford "Roland.": “Hopper points out that duodecads have been prominent in…”.