Bachelor
A bachelor is a man of legal age who's never married.
The word is first attested as the 12th-century bacheler, a knight bachelor, a knight too young or poor to gather vassals under his own banner. The Old French bacheler presumably derives from Provençal bacalar and Italian baccalare, but the ultimate source of the word is uncertain. The proposed Medieval Latin *baccalaris ("vassal", "field hand") is only attested late enough that it may have derived from the vernacular languages, rather than from the southern French and northern Spanish Latin baccalaria ("cattle ranch", from bacca, "cow"). Alternatively, it has been derived from Latin baculum ("a stick"), in reference to the wooden sticks used by knights in training.