also: すわい
Records from the Edo period show that 牙婆 acted as intermediaries in transactions.
Archaic kanji spelling for a historical broker or brokerage fee. The reading すわい is restricted to this form.
Alternate archaic kanji spelling. The reading すあい is used with this form.
Another archaic kanji spelling. The reading すあい is used with this form.
The exact derivation is uncertain. The kanji 牙 (tusk, fang) and 婆 (old woman) may have been used phonetically or as ateji for the reading すわい/すあい, which likely originated from a native Japanese word for mediation or fee.