noun
bottom knock of a bow
Refers to the lower tip of a Japanese bow where the string is attached. A specialized archery term.
弓の本弭に弦をかける。
String the bow by attaching the string to the bottom knock.
末弭 is the top knock of a bow, while 本弭 is the bottom knock.
Compound of 本 (moto, 'base') and 弭 (hazu, 'bow tip'). The reading もとはず is a regular rendaku form.