the event consisting of the start of something

take the first step or steps in carrying out an action

set in motion, cause to start

bring into being

get off the ground

begin work or acting in a certain capacity, office or job

the increase in activity of the adrenal glands just before puberty

the first occurrence of menstruation in a woman

the start of breast development in a woman at the beginning of puberty

the beginning or early stages

the earliest period