cap

The word 'cap' is among the oldest surviving Latin borrowings in English, entering the language in the Old English period as 'cæppe,' meaning a hood or head covering.‌​‍​‌​‍​‌​‍​‍​‍​‌​‍​‍​‌​‍​‌​‌​‍​‌​‍​‍​‌​‍​‌​‌​‌​‍​‍​‌​‍​‍​‌​‍​‍ It came from Late Latin 'cappa,' a word for a hooded cloak or cape that became enormously productive in the Romance languages and beyond.

The ultimate origin of Late Latin 'cappa' is debated. The most widely accepted theory connects it to Latin 'caput' (head), from the Proto-Indo-European root *kaput-, meaning 'head.' The logic is straightforward: a 'cappa' was a garment associated with the head — either a hood or a cloak with a hood. Some scholars have proposed a non-Indo-European substrate origin, noting that garment words sometimes resist neat etymological analysis. But the semantic and phonological connection to 'caput' remains the dominant view.

The PIE root *kaput- produced one of the largest word families in English, almost entirely through the Latin channel. 'Capital' (pertaining to the head — hence the head city, head crime, or accumulated wealth), 'captain' (a headman), 'chapter' (from Latin 'capitulum,' a little head or heading), 'cadet' (from Gascon 'capdet,' a little head or chief), 'chef' (the French reflex of 'caput,' meaning head — hence head cook), 'chief' (the Norman French reflex), 'cattle' (from medieval Latin 'capitale,' property, literally 'head' as in 'head of cattle'), 'chattel' (a doublet of 'cattle'), and 'decapitate' (to remove the head) all stem from the same source.

The word 'escape' carries a particularly vivid image from this root. It comes from Vulgar Latin *excappāre, literally 'to get out of one's cape' — the idea being that if a pursuer grabs your cloak, you slip out of it and flee, leaving the empty garment in their hands.

In Old English, 'cæppe' referred primarily to a hood or close-fitting head covering, as distinct from a 'hæt' (hat), which was a broader covering. This distinction persists in modern English: caps are generally soft and close-fitting, while hats have brims or more structured shapes, though the boundary is fuzzy.

The word 'cap' developed rich figurative extensions. 'To cap' a story means to surpass it with a better one — to put a cap or lid on top. 'To set one's cap at' someone (to try to attract them romantically) dates from the eighteenth century. 'Nightcap' originally meant a cap worn in bed, then became a final drink before bed. A 'cap' in sports (especially British English) refers to a player's selection for a national team, from the tradition of giving selected players a literal cap.

The related word 'cape' (a sleeveless cloak) is a doublet — the same Late Latin 'cappa' borrowed again through a different route, this time through Provençal and Spanish. 'Chapel' and 'chaplain' also descend from 'cappa': the Frankish kings' 'capella' (little cloak) referred originally to the shrine where the relic of Saint Martin's cloak was kept, and 'capellānus' (chaplain) was its guardian.

The humble English monosyllable 'cap' thus sits at the center of a vast etymological web connecting headgear to leadership, property, escape, cooking, worship, and sport — all radiating from the ancient association between coverings and the head they cover.