The first appearance of pubic and axillary hair in a child, occurring as a result of increased hormone synthesis by the adrenal cortex; the time at which this occurs, typically around eight years of age.
Origin
1940s. From adren- + -arche. Compare pubarche.
Definition of adrenarche in US English:
adrenarche
nounˌadrɪˈnɑːki
Medicine
The first appearance of pubic and axillary hair in a child, occurring as a result of increased hormone synthesis by the adrenal cortex; the time at which this occurs, typically around eight years of age.