the day of the week after Sunday and before Tuesday, the first day of the working week It's Monday today, isn't it? She started work last Monday. Are you busy next Monday? Monday morning/afternoon/evening We'll discuss this at Monday's meeting. Do we still have Monday's paper? I work Monday to Friday. I work Mondays to Fridays. On Monday(s) (= Every Monday) I do yoga. I always do yoga on a Monday. He was born on a Monday. I went to Paris on Thursday, and came back the following Monday. We'll meet on Monday. (British English) ‘When did the accident happen?’ ‘It was the Monday (= the Monday of the week we are talking about).’ (British English) Come back Monday week (= a week after next Monday). (informal or North American English) We'll meet Monday. From the Old English for ‘day of the moon’, translated from Latin lunae dies.