According to the Merriam Webster dictionary this word means "short-headed or broad-headed with a cephalic index of over 80".
According to the Etymology dictionary the word "Brachycephalic" is formed of two words: "Brachy" word-forming element meaning "short," from Latinized comb. form of Greek brakhys "short" and "Cephalic" pertaining to the head, from Latin cephalicus and from Greek kephalikos "pertaining to the head," from kephale.
Other words referring to "Brachy" are: brachyfacial, brachypterous and brachytherapy. Other words referring to "Cephalic" are: acephalia, encephalic and hypsicephalic.
You can see the use of this word in this article.
Roberto Riobó Juega 3ºA