Where does “cerebrous” come from?

cerebrous (English) comes from English cerebrum, from Middle English cerebrum, from Latin cerebrum, from Proto-Italic kerazrom, from Proto-Indo-European ḱerh₂-s-ro, from Proto-Indo-European ḱerh₂- — head, top; horn.

Ancestry of “cerebrous”, step by step

StepLanguageWordMeaning
1EnglishcerebrumThe upper part of the brain, which is divided...
2Middle Englishcerebrumbrain
3Latincerebrumbrain; skull
4Proto-Italickerazrombrain
5Proto-Indo-Europeanḱerh₂-s-ro—
6Proto-Indo-Europeanḱerh₂-head, top; horn
Every word from Proto-Indo-European ḱerh₂- →Every word from Proto-Indo-European ḱerh₂-s-ro →Every word from Proto-Italic kerazrom →