lumbago UK /lʌmˈbeɪɡəʊ/US /ˌlʌmˈbeɪˌɡoʊ/noun 2verb 1forms 3 noun[before a noun]2 •Backache of the lumbar region or lower back, which can be caused by muscle strain or a slipped disc.Sir Oswald Feiling winced as he turned to go home. He had felt a warning twinge of lumbago. — 1935 •An episode of such backache. verb[before a noun]1 •To affect (someone) with lumbago. formslumbagoed · lumbagoing · lumbagos