About the name Guillermo
Guillermo belongs to the Spanish tradition. Its roots are documented, even though its precise meaning is not recorded in the standard references — an honest gap we prefer to a confident guess.
In the United States, Guillermo first appears in Social Security records in 1885. It climbed to its best-ever rank of #352 in 1996, and in 2024 297 babies received the name — 31,807 in total since 1880. Those are the official counts, not estimates.