aid n.

word-forming element expressing direction toward or in addition to, from Latin ad "to, toward" in space or time; "with regard to, in relation to," as a prefix, sometimes merely emphatic, from PIE root *ad- "to, near, at."

Simplified to a- before sc-, sp- and st-; modified to ac- before many consonants and then re-spelled af-, ag-, al-, etc., in conformity with the following consonant (as in affection, aggression). Also compare ap- (1).

In Old French, reduced to a- in all cases (an evolution already underway in Merovingian Latin), but French refashioned its written forms on the Latin model in 14c., and English did likewise 15c. in words it had picked up from Old French. In many cases pronunciation followed the shift.

Over-correction at the end of the Middle Ages in French and then English "restored" the -d- or a doubled consonant to some words that never had it (accursed, afford). The process went further in England than in France (where the vernacular sometimes resisted the pedantic), resulting in English adjourn, advance, address, advertisement (Modern French ajourner, avancer, adresser, avertissement). In modern word-formation sometimes ad- and ab- are regarded as opposites, but this was not in classical Latin.

Old English geong "youthful, young; recent, new, fresh," from Proto-Germanic *junga- (source also of Old Saxon and Old Frisian jung, Old Norse ungr, Middle Dutch jonc, Dutch jong, Old High German and German jung, Gothic juggs), from PIE *yuwn-ko-, suffixed form of root *yeu- "vital force, youthful vigor" (source also of Sanskrit yuvan- "young; young man;" Avestan yuuanem, yunam "youth," yoista- "youngest;" Latin juvenis "young," iunior "younger, more young;" Lithuanian jaunas, Old Church Slavonic junu, Russian junyj "young," Old Irish oac, Welsh ieuanc "young").

From c. 1830-1850, Young France, Young Italy, etc., were loosely applied to "republican agitators" in various monarchies; also, especially in Young England, Young America, used generally for "typical young person of the nation." For Young Turk, see Turk.