This refers to the labia of the vagina in Luganda. Luganda is a language from Uganda. Luganda is the second most language after English in Uganda. It is widely spoken among the Baganda who comprise one of the tribes in Uganda.
Okusika enfuli i.e. to elongate the labia. this practise of labia elongation is practised mainly among the Baganda women from adolescence. It's performed by mainly paternal aunties known as ssenga. The practise is believed to increase sexual pleasure during coitus.