the state or period of being an infant; very early childhood, usually the period before being able to walk; babyhood.

the corresponding period in the existence of anything; very early stage

Space science is in its infancy.

infants collectively.

Law . the period of life to the age of majority, 21 years at common law but now usually 18; minority; nonage.

noun

nonage , babyhood , beginning , childhood , immaturity , inception , incunabulum , minority , outset , pupilage , start