Emily Dickinson Lexicon

KNOCK, v.i. [nok; Sax. cnucian; W. cnociaw; Sw. knacka.]

1. To strike or beat with something thick or heavy; as, to knock with a club or with the fist; to knock at the door. We never use this word to express beating with a small stick or whip.
2. To drive or be driven against; to strike against; to clash; as when one heavy body knocks against another. To knock under, to yield; to submit; to acknowledge to be conquered; an expression borrowed from the practice of knocking under the table, when conquered. – Johnson.