Definition of irwin:
(n) :
A Scottish or Irish surname originating as a patronymic.
(n) :
A male given name transferred from the surname.
(n) :
A number of places in the United States:
(n) :
A local government area, the Shire of Irwin, in the Mid West region, Western Australia.
(n) :
An unincorporated community in Merced County, California.
(n) :
A minor city in Bonneville County, Idaho.