Green’s Dictionary of Slang

fake, spurious, sham.

1906		Marvel 21 Apr. 345: Don’t yer berlieve me? And I was goin’ ter ’elp yer, too! I berlieve it’s all spoof!
1919		J. Buchan Mr Standfast (1930) 651: I remember wondering what these sportsmen got for their testimonies, and thinking I would write a spoof letter myself to old Gussiter.
1928		J. Agate Gemel in London 107: It cannot distinguish between the spoof expression and the real thing.
1997		N. Barlay Curvy Lovebox 109: Iss like of them spoof shows innit: The GangstaGuys.
2000		Guardian Rev. 22 Jan. 4: His Johnny Cash spoof song.