noun
lucky underwear; special-date panties
Colloquial term for underwear (especially panties) set aside for dates or occasions when one hopes to 'win' romantically. Often implies a playful, slightly superstitious mindset.
See also: 勝負服
今日はデートだから、勝負下着を履いてきた。
I have a date today, so I wore my lucky underwear.
彼女は勝負下着を買うために下着売り場へ行った。
She went to the lingerie section to buy special-date panties.