What origin is the name Guillelmus?

Guillelmus comes from International naming traditions. Names from this origin often carry meanings tied to nature, virtues or heritage.

What are good sister names for Guillelmus?

Names from the same international tradition pair naturally with Guillelmus — for example Nautica, Arica, Laisha. You can browse more on our international names page.

Guillelmus

Discover the meaning and origin of the name Guillelmus

Guillelmus

Boy

International

3 syllables

Guillelmus is an International boy's name meaning "Resolute protector".

With International roots, Guillelmus is a boy name that means "Resolute protector". At 10 letters it is a longer name, which leaves room for a nickname. It has 3 syllables.

Origin: International
Gender: Boy
Syllables: 3

Last updated 24 October 2026.

Meaning

Resolute protector

Popularity

No birth-record data (source: not in US birth records; popularity in India is not tracked)

Quick answers about Guillelmus

What does Guillelmus mean?

Guillelmus is a boy name of International origin meaning "Resolute protector".

How popular is Guillelmus?

We have no birth-record ranking for Guillelmus: it is not in US records, and India publishes no national name rankings. The meter above fills in as parents here view, search for and save the name.

Sister names that go with Guillelmus

Nautica Arica Laisha Latrina Fredia Shaelyn

How to say Guillelmus

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Name numerology

1is the Chaldean number for Guillelmus.

Number 1 is linked with leadership, independence and new beginnings.

More names with number 1

Numerology is a cultural tradition for fun, not a prediction.

Compare Guillelmus with other names

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Names with a similar meaning to Guillelmus

Guillelmus means "Resolute protector" — these names share that spirit.

Liam — "Liam is the Irish short form of William, from Germanic words meaning 'will' and 'helmet', so 'resolute protector'." (Irish)
William — "William comes from the Germanic Willahelm, from wil 'will, desire' and helm 'helmet, protection', so 'resolute protector'." (German)

More names by meaning: Boy Names That Mean Protector & Guardian