shag5Pronunciation: /ʃag/ British vulgar slangDefinition of shag verb (shags, shagging, shagged) [with object] have sexual intercourse with (someone). [no object] (of two people) have sexual intercourse. noun an act of sexual intercourse. [with adjective] a sexual partner of a specified ability. Derivatives shaggable adjective shagger noun Origin: late 18th century: of unknown originshag in other Oxford dictionaries Definition of shag in the US English dictionary