advertisement n.

early 15c., advertisen, "to take notice of" (a sense now obsolete), from Old French advertiss-, present-participle stem of advertir (earlier avertir) "make aware, call attention, remark; turn, turn to" (12c.), from Latin advertere "to direct one's attention to; give heed," literally "to turn toward," from ad "to, toward" (see ad-) + vertere "to turn" (see versus).

The transitive sense of "give notice to others, inform, warn; make clear or manifest" (mid-15c.) is by influence of advertisement; the specific commercial meaning "call attention to goods for sale, rewards, etc." emerged by late 18c. Compare advert (v.) "turn (someone's) attention to."  Related: Advertised; advertising.

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.