wearing only a loincloth; nothing but a loincloth
Often used in the pattern 〜で, 〜の, or 〜になり to describe a state of undress where someone is wearing nothing except a traditional Japanese loincloth (fundoshi).
See also: パンツ一丁 · ふんどし一丁 (ふんどしいっちょう)
He jumped into the river wearing nothing but a loincloth.
At the festival, the men carry the portable shrine dressed only in loincloths.
Standard kanji-kana mixed spelling.
Kana spelling for the first part; this is a written variant.
Compound of 褌 (fundoshi, 'loincloth') + 一つ (hitotsu, 'one'), literally 'one loincloth', implying nothing else is worn.