brachycephalic

nouns

an adult with a short broad head
brachycephalic
is a type of (narrower)
a fully developed person from maturity onward
adult, grownup

adjectives

having a short broad head with a cephalic index of over 80
brachycephalic, brachycranial, brachycranic
is derived from
brachycephaly
antonym
dolichocephalic