What does Guillaume mean?
Guillaume /guil-lau-me/ as a boys' name is pronounced gee-OHM. It is of Old German origin, and the meaning of Guillaume is "determined protector". French variant of William. French poet Guillaume Apollinaire.
(male) Gillaume, Guilmo, ..
(female) Guillaudi, Guillaune, ..
How popular is Guillaume?
Guillaume is a rare given name for men but a very popular last name for both adults and children (#11719 out of 150436, Top 8%). (2000 U.S. Census)
Guillermo (#678 in recent rankings) and William (#5) are the popular alternative forms of Guillaume (not ranked). Adoption of these relations of Guillaume reached its peak during 1880-1889 (median #939) and is now much reduced (#341, ▼88.4%). Below is a graphed analysis of the history of Guillaume and corresponding names. (Top Baby Names, 2014)