expression, i-adjective
generous; big-hearted; broad-minded; magnanimous
Describes a person who is tolerant, not easily upset, and forgiving. Literally 'stomach is thick', suggesting emotional resilience and capacity.
彼は腹が太いから、少々の失敗では怒らない。
He is big-hearted, so he doesn't get angry over small mistakes.
The more broad-minded a person is, the more they are trusted by others.