shag: [OE] Shag originally meant ‘rough untidy hair’, a sense now more familiar in its derivative shaggy [16]. Related Old Norse forms such as skegg ‘beard’, skagi ‘promontory’, and skaga ‘project’ suggest that its underlying meaning is ‘something that sticks out’. The bird-name shag, which denotes a relative of the cormorant and was first recorded in the 16th century, may be an allusion to the bird’s shaggy crest. The origins of the verb shag ‘copulate with’, which dates from the late 18th century, are not known, although it may be distantly related to shake.
