To Strike, To Hit
transitive verb, godan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means assault. What are some ways to assault a person? How about to punch, to strike, or to hit, to name a few?
Someone is nagging (なぐ) you and nagging you about something. You can't take it any more, so you turn around to punch them in the face.
The moment the gong sounded, the boxer punched his opponent’s jaw with all his strength.