Synonyms for Thong (same or very similar meaning)
WordNet sense 1 (leather strip that forms the flexible part of a whip):
lashWordNet sense 2 (minimal clothing worn by stripteasers; a narrow strip of fabric that covers the pubic area, passes between the thighs, and is supported by a waistband):
G-stringWordNet sense 3 (a backless sandal held to the foot by a thong between the big toe and the second toe):
flip-flopFrom the ODE community, based on WordNetadd/edit