IOU
noun/ˌaɪ əʊ ˈjuː/
/ˌaɪ əʊ ˈjuː/
(informal)- a written promise that you will pay somebody the money you owe them (a way of writing ‘I owe you’)
借据，欠条（表示 I owe you） - an IOU for £100
100 英镑的借据
Word Originlate 18th cent.: representing the pronunciation of I owe you. - an IOU for £100