Refers to the early morning hours. Often used in the phrase 朝腹に (in the early morning).
See also: 朝っぱら
empty stomach in the morning
Archaic term for an empty stomach before breakfast. Rarely used in modern Japanese.
triviality; simple matter
Archaic meaning referring to something trivial or easy, often used in the phrase 朝腹の (trivial).
That is a trivial matter.
Taking a walk in the early morning is my daily routine.
It is said that people in the past took medicine on an empty stomach in the morning.
The word 朝腹 is composed of 朝 (morning) and 腹 (stomach). The exact historical derivation is uncertain, but the meanings likely developed from the idea of the morning stomach (empty stomach) to early morning and then to triviality.