dun

adjective

noun

1. a dull grayish brown
2. a dun horse
3. an artificial fishing fly of this color
4. mayfly

transitive verb, intransitive verb dunned, dunning

1. to ask (a debtor) insistently or repeatedly for payment
2. to annoy constantly

noun

1. a person who duns
2. an insistent demand, esp. for payment of a debt