Aid is a French word with a Latin skeleton showing through. Latin adiuvare meant "to give help to," built from ad, "to," plus iuvare, "to help, support, sustain." That became adiuta in Late Latin, aiudha and then aide in Old French, and aide in English by the early 1400s. The modern spelling has lost the Latin d and v entirely, which is why aid looks nothing like its relatives adjutant and coadjutor — they came into English later and more directly, so they kept more of the Latin shape.
The oldest English sense is a reminder of what the Norman ruling class used the language for: a wartime tax. The general sense of help and support was there from the start too, and the word steadily grew concrete — the thing that gives assistance from the 1590s, the person who gives it from the 1560s, and material help sent from one country to another only from 1940.
aid (n.) early 15c., aide , "war-time tax," also "help, support, assistance," from Old French aide , earlier aiudha "aid, help, assistance," from Late Latin adiuta , noun use of fem. of adiutus , past participle of Latin adiuvare "to give help to," from ad "to" (see ad- ) + iuvare "to help, give strength, support, sustain," which is from a PIE source perhaps related to the root of iuvenis "young person" (see young (adj.)). The meaning "thing by which assistance is given" is recorded from 1590s; the sense of "person who assists, helper" is from 1560s. The meaning "material help given by one country to another" is from 1940. also from early 15c. aid (v.) "to assist, help," c. 1400, aiden , from Old French aidier "help, assist" (Modern French aider ), from Latin adiutare , frequentative of adiuvare (past participle adiutus ) "to give help to," from ad "to" (see ad- ) + iuvare "to help, assist, give strength, support, sustain," which is from a PIE source perhaps related to the root of iuvenis "young person" (see young (adj.)). Related: Aided ; aiding . also from c. 1400
aid came in through Norman French, and its spelling follows that family's conventions.
On the register ladder
English kept all three words for this idea, one from each layer, and the rung is itself the cue: the native word is blunt and concrete, the French one polite, the Latin one formal or technical.
| Old English | French | Latin |
|---|---|---|
| help | aid | assist |
Norman French in the spelling guide · guess another word's family