A lap-lap is a waistcloth or loincloth worn in Papua New Guinea and the South Pacific. This item of clothing has three parts: a front flap, a back flap, and a thread to tie them around the waist. The sides are generally open. How much is covered by the front and back flaps varies.
Related to the lap-lap is the lava-lava, which is an all-round rectangular cloth worn like a kilt or skirt by Polynesians.
References
Lap-lap Wikipedia(Text) CC BY-SA