"open declaration, frank acknowledgment," 1716, from avow + -al (2).
Entries linking to avowal
avow v.
c. 1300, "uphold, support, approve; stand by, back up (someone); declare openly, take sides openly, affirm;" mid-14c. "admit openly," from Anglo-French avouer, Old French avoer "acknowledge, accept, recognize," especially as a protector (12c., Modern French avouer), from Latin advocare "to call, summon, invite" (see advocate (n.)). A synonym of avouch (q.v.), which tends to contain the more technical, legal aspect of the word. Related: Avowed; avowing.
-al 2
suffix forming nouns of action from verbs, mostly from Latin and French, meaning "act of ______ing" (such as survival, referral), Middle English -aille, from French feminine singular -aille, from Latin -alia, neuter plural of adjective suffix -alis, also used in English as a noun suffix. Nativized in English and used with Germanic verbs (as in bestowal, betrothal).