出典:Wiktionary
From Middle English avowen, from Old French avouer, from Latin advocare (“to call to, call upon, hence to call as a witness, defender, patron, または advocate”), from ad (“to”) + vocare (“to call”). Doublet of advoke, avouch, and advocate. Not related to vow.
avow (三人称単数 現在形 avows, 現在分詞 avowing, 過去形および過去分詞形 avowed)
avow