Where does “Gilliam” come from?

Gilliam comes from Anglo-Norman Willame, a variant form of William whose ultimate origin and meaning remain uncertain.

Ancestry of “Gilliam”, step by step

StepLanguageWordMeaning
1EnglishWilliamradiotelephony clear-code word for the letter W
2Anglo-NormanWillame
3Old High GermanWillahelmWilliam
4Old High Germanhelmhelmet
5Proto-West Germanichelmhelmet
6Proto-Germanichelmazhelmet
7Proto-Germanichalmazhalm; stem; stalk; straw; hay
8Proto-Indo-Europeanḱolh₂mosstalk
9Proto-Indo-Europeanḱelh₂-to pierce, strike; to stick; prick; stab

Words derived from “Gilliam

Every word from Proto-Indo-European ḱelh₂-Every word from Proto-Indo-European ḱolh₂mosEvery word from Proto-Germanic halmaz