Nag

Part of speech: noun (n.)

1. A small horse; a pony; hence, any horse.

2. A paramour; -- in contempt. [Obs.] Shak.

Part of speech: verb (v.)

To tease in a petty way; to scold habitually; to annoy; to fret pertinaciously. [Colloq.] "She never nagged." J. Ingelow.