coolibahPronunciation: /ˈkuːlɪbɑː/ (also coolabah)Definition of coolibah noun a North Australian gum tree which typically grows near watercourses and yields very strong, hard timber. Eucalyptus microtheca, family Myrtaceae Origin: late 19th century: from Kamilaroi (and related languages) gulubaacoolibah in other Oxford dictionaries Definition of coolibah in the US English dictionary