noun which may take the genitive case particle 'no', na-adjective, noun
age of wisdom; age of sound judgment
Describes a person who has reached an age where they are expected to have mature judgment and common sense. Often used in literary or reflective contexts.
彼も分別盛りになったから、もう無茶はしないだろう。
He has reached the age of wisdom, so he probably won't do anything reckless anymore.
分別盛
As an adult of sound judgment, you should handle this calmly.