Green’s Dictionary of Slang

1. (US) a man who is showing a slice of flesh above the top of his trousers [smile n.² (2)].

1989

P. Munro Sl. U. 175: Smiley name for a guy with a working man’s smile.

2. (S.Afr.) a sheep’s or goat’s head (sometimes split in half), cleaned and grilled or stewed with or without the tongue and brain [the ‘grinning’ aspect of the cooked head].

1990		J. Cullum in Weekend Post 18 Aug. 7: At the entrance to Njoli square, half a stewed goat’s head (known as a ‘Smiley’) costs R2.50 [DSAE].
1994		E. Badenhorst in Flying Springbok June 9: The only spanner in our spokes was a very kind ‘gift’ Iyavaya decided to bestow on us — a ‘smiley’. This is local slang for a grilled sheep’s head — apparently a local township speciality [DSAE].