Green’s Dictionary of Slang

1. (Aus.) a fool.

1890		‘Rolf Boldrewood’ Colonial Reformer I 202: What a regular more-pork I was to be sure.
1903		J. Furphy Such is Life 112: What an advantage it would be if man, figuratively a mopoke, could become one in reality when all the advantage lay in that direction.
c.1905		J. Furphy Rigby’s Romance (1921) Ch. viii: 🌐 To (sheol) with you an’ yer (adj.) Land o’ Canaan, you blatherin’ morepoke.
1910		Bulletin (Sydney) 15 Dec. 23/1: Listen to this, you –, you – mopoke!
1917		‘Henry Handel Richardson’ Aus. Felix (1971) 41: Golly, Dick, that’s no mopoke! [...] A crafty devil, if ever I see’d one.
1936		(con. 1830s–60s) ‘Miles Franklin’ All That Swagger 154: Billy was eager to follow Fullwood to Hell or Hay in order ‘to belt the stuffin’ outer the -- ole morepork’.
1948		R. Park Harp in South 61: ‘I’d like to see your throat cut by a buck nigger, you old morepork’.
1951		D. Stivens Jimmy Brockett 255: I’d got miserable as a mopoke wondering if I was slipping.
1959		D. Niland Gold in the Streets (1966) 168: Don’t be a morepork, Pudden.
1992		R. Park Fence Around the Cuckoo 94: That blasted morepork drove the tip-truck over a cutting at the Three Mile! The lorry was totalled.

2. (N.Z. prison) an inmate who prefers to remain in their cell.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 119/1: morepork n. an inmate who remains constantly in his cell.