a ‧ vow /əˈvaʊ/ BrE AmE verb [transitive]
[ Date: 1200-1300 ; Language: Old French ; Origin: avouer , from Latin advocare ; ⇨ ↑ advocate 2 ]
formal to make a public statement about something you believe in SYN swear :
He avowed his commitment to Marxist ideals.
—avowal noun [uncountable and countable]