A triple-threat portmanteau combining the words
Thick,
Thong, and Showing (or Going). It specifically describes the visual phenomenon where a
woman’s buttocks are large enough to completely "swallow" or obscure the thong she is wearing.
Instead of the full waistband being visible, the fabric is hidden by her "thickness," leaving only a small portion—like the
top of the "T" or the back triangle—peering out.
The term also plays on the slang "Going" or "Goer," referring to a
woman who is high-energy and sexually active. When a girl is "thoing," the garment is practically invisible or "gone" due to her size, signaling she is a "goer" who is "showing" just enough to be a teaser.
"My girl walking around the
spot thoing as hell right now; she's so
thick you can't
even see the strings, just the 'T' at the top."