[UNDER-1 5 b.] The hold obtained by a wrestler who gets his arms below those of his opponent.
1870. J. De Mille, The Boys of Grand Pré School, viii. 122. Then Bruce made a plunge forward, and before the other could guard against it, he had caught him around the waist, under his arms.
Bruce had got the underhold.
1895. Funks Stand. Dict.