1. To jerk off, to masturbate, used as a vigorous metaphor for male masturbation, focusing on the friction, energy, or frantic motion involved; 2. To fuck, to bang.
Выбежал Ярилко из-за печного столба, начал бабу ярить, только палка стучит.
Yarilko ran out from behind the stove post, started fucking the old woman, only the schlong was knocking.
