Green’s Dictionary of Slang

(S.Afr.) a soldier, esp. the lowest rank of national serviceman.

1972		Eng. Usage in S. Afr. VI:1: Some of the troepies with particularly dirty habits [...] receive the title vuilgat... Of course some ‘troepies’ are impatient for their period of service to end [DSAE].
1978		Time 27 Feb. 38: Whether tracking guerillas by day or setting up ambush positions at night, the ‘troopies’ communicate by hand signals.
1987		(con. 1967) Bunch & Cole Reckoning for Kings (1989) 174: Bling Pig always figured you took more troopies out when you wounded them than when they were nice and quietly dead.
1990		P. Hotz Muzukuru 35: Two troopies, both of them drunk, swagger up to our table.
2006		A. Dowds Red Car Diaries 92: My own limited experience as a reluctant ‘troepie’ with the SADF gave me an idea.