noun

1. A musical instrument consisting of a body and a curved neck, strung with strings of varying length that are stroked or plucked with the fingers and are vertical to the soundboard when viewed from the end of the body

2. A harmonica.

3. A grain sieve.

verb

1. (usually with on) To repeatedly mention a subject.

   “Why do you harp on a single small mistake?”

2. To play on (a harp or similar instrument)

3. To play (a tune) on the harp.

Synonyms: keep on, perseverate