Geertrudus

Geertrudus is a masculine form derived from the Old High German name *Geretrudis*, which is the root of the more common feminine name Gertrude. The elements are *ger* meaning 'spear' and *þrūþ* (or *trud*) meaning 'strength'. While Gertrude became widely popular, especially in medieval Europe, its masculine counterpart Geertrudus remained much rarer and is primarily found in Dutch-speaking regions, often as a formal or baptismal name. It reflects a historical practice of creating masculine versions of popular feminine names, though these often did not achieve the same level of widespread use.

The name's usage is largely confined to historical records and formal documents, particularly within the Netherlands and Belgium. It is not a name that has seen a revival in modern times and is considered quite archaic. Its existence highlights the linguistic connections between Germanic names and the evolution of gendered forms.