dun

1
[ duhn ]
/ dʌn /

verb (used with object), dunned, dun·ning.

to make repeated and insistent demands upon, especially for the payment of a debt.

noun

a person, especially a creditor, who duns another.
a demand for payment, especially a written one.

Origin of dun

1
First recorded in 1620–30; origin obscure
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for dunning

British Dictionary definitions for dunning (1 of 2)

dun1
/ (dʌn) /

verb duns, dunning or dunned

(tr) to press or importune (a debtor) for the payment of a debt

noun

a person, esp a hired agent, who importunes another for the payment of a debt
a demand for payment, esp one in writing

Word Origin for dun

C17: of unknown origin

British Dictionary definitions for dunning (2 of 2)

dun2
/ (dʌn) /

noun

a brownish-grey colour
a horse of this colour
angling
  1. an immature adult mayfly (the subimago), esp one of the genus Ephemera
  2. an artificial fly imitating this or a similar fly

adjective dunner or dunnest

of a dun colour
dark and gloomy

Word Origin for dun

Old English dunn; related to Old Norse dunna wild duck, Middle Irish doun dark; see dusk
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012