late 14c., amonicioun "reminding, instruction," from Old French amonicion "admonition, exhortation," from Latin admonitionem (nominative admonitio) "a suggestion, a reminding; an admonition," noun of action from past-participle stem of admonere "to advise, warn" (see admonish).
The -d- was restored in French, then (17c.) in English. The meaning "caution or warning about future conduct based on past failures" is by early 15c.
updated on September 15, 2022