numbing — deprived of physical sensation or the ability to move: fingers numb with cold.
plumbing — a small mass of lead or other heavy material, as that suspended by a line and used to measure the depth of water or to ascertain a vertical line. Compare plumb line.
punning — the humorous use of a word or phrase so as to emphasize or suggest its different meanings or applications, or the use of words that are alike or nearly alike in sound but different in meaning; a play on words.
thumbing — the short, thick, inner digit of the human hand, next to the forefinger.
tonguing — Anatomy. the usually movable organ in the floor of the mouth in humans and most vertebrates, functioning in eating, in tasting, and, in humans, in speaking.
Three-syllable rhymes
becoming — A piece of clothing, a colour, or a hairstyle that is becoming makes the person who is wearing it look attractive.
forthcoming — coming, forth, or about to come forth; about to appear; approaching in time: the forthcoming concert.
Four-or-more syllable rhymes
second coming — the coming of Christ on Judgment Day.
unbecoming — detracting from one's appearance, character, or reputation; unattractive or unseemly: an unbecoming hat; unbecoming language.