loon verb to fool about; to move to music in an uncontrolled manner Often followed by “about” UK,1966
— Jenny Fabian and Johnny Byrne, Groupie, 1968
The hippy penchant for play survives in the way sisters [in the Women’s Lib movement] enjoy “bopping” and “looning” together, that is, dancing and clowning around for fun. — Angela Carter, TheState oftheLanguage, 1980