качнуть

Possibly кача́ть (kačátʹ) +‎ -ну́ть (-nútʹ) (or derived the other way around).

• IPA^(key): [kɐt͡ɕˈnutʲ]
• Rhymes: -utʲ

качну́ть • (kačnútʹ) pf (imperfective кача́ть)

1. to rock, to swing, to shake, to wobble; to dandle (once)

   качну́ть колыбе́ль ― kačnútʹ kolybélʹ ― to rock the cradle (once)

   качну́ть голово́й ― kačnútʹ golovój ― to shake one's head (once)

   • 1973, Михаил Булгаков, “Глава II. Понтий Пилат”, in Мастер и Маргарита; English translation from Richard Pevear and Larissa Volokhonsky, transl., Master and Margarita, London: Penguin Books, 1997:

     Прокуратор был как каменный, потому что боялся качнуть пылающей адской болью головой.

     Prokurator byl kak kamennyj, potomu što bojalsja kačnutʹ pylajuščej adskoj bolʹju golovoj.

     The procurator was as if made of stone because he was afraid to move his head, aflame with infernal pain.

2. to pump (once)
3. (transitive or impersonal) to toss, to roll, to pitch (once)

   ло́дку качну́ло ― lódku kačnúlo ― the boat tossed / rolled (once)

4. (colloquial) to lift up, to chair (to toss someone up, like a group of fans their champion)
5. (colloquial) to train/pump muscle (once)

• качну́ться pf (kačnútʹsja)

• ка́чка (káčka)
• кача́ние (kačánije)