Green’s Dictionary of Slang

strop n.

[stroppy adj.]

1. (S.Afr.) trouble, ‘backchat’, obstreperous behaviour.

[SA]C. Hope Ducktails in Gray Theatre Two (1981) 47: I told you not to gooi me any more strop, Bo-bo.
[SA]P. Slabolepszy Sat. Night at the Palace (1985) 13: So because I want to stuff him up, Carstens has a big shit from the bench. Says I mustn’t cause strop.

2. a bad temper.

[UK]G. Burn Happy Like Murderers 326: When Fred got depressed or had a strop on him he grew his hair.
[Ire]P. Howard Curious Incident of the Dog in the Nightdress 64: So off they go, roysh, in a total strop.