Ｔバック

noun

T-back; thong; bikini thong

A garment, especially underwear or swimwear, whose back part is narrow or T-shaped like a thong. Not vulgar, but the topic can be intimate or clothing-specific.

• この水みず着ぎは後うしろがＴバックになっている。

  This swimsuit has a T-back at the back.

• Ｔバックの下した着ぎはラインが出でにくい。

  T-back underwear is less likely to show panty lines.