IOU

IOU

Noun · /ˌaɪ.əʊˈjuː/

Definition

An informal acknowledgement of a debt, usually a written note with the letters IOU (representing 'I owe you') stating the amount owed and the debtor's name.

Origin

The abbreviation IOU represents the spoken phrase 'I owe you'. The letters were used as early as the 18th century in Britain as a written informal debt acknowledgement. The phrase entered common usage in English by the early 19th century.