Real Dictionary

shag
countable noun: A shag is a black seabird with a yellow beak, found mainly in Europe and North Africa.
verb: If someone shags another person, or if two people shag, they have sex together.

shag in American English 1
heavily matted wool or hair
to make or become rough or shaggy
to make shaggy or rough
noun: rough, matted hair, wool, or the like

shag in American English 2
any of several cormorants, esp. an American double-crested species (Phalacrocorax auritus) or a European species ( P. aristotelis)
noun: a small cormorant, Phalacrocorax aristotelis, of European coasts

shag in American English 3
to chase after and retrieve (baseballs hit in batting practice)
intransitive verb: to dance a step with a vigorous hopping on each foot
noun: this dance step

shag in American English 4
an act or instance of sexual intercourse
to have sexual intercourse with
transitive verb: to chase or follow after; pursue

shag in British English 1
noun: a matted tangle, esp of hair, wool, etc
verb: to make shaggy

shag in British English 2
noun: a cormorant, esp the green cormorant (Phalacrocorax aristotelis)