Febra likely relates to Latin februa, associated with purification and the Roman month-name February.
Febra likely relates to the Latin februa, a word tied to purification, and by extension to February, the Roman month associated with cleansing rites. That gives the name a calendar-and-ritual background rather than a simple personal-name lineage.
Because of that, Febra feels both ancient and slightly enigmatic, as though it comes from a fragment of classical vocabulary that has been repurposed into a name. As a given name, it has a crisp, modern shape that hides its older associations. Febra feels cool, spare, and a little mysterious, with an undertone of renewal rather than ornament.
It is uncommon enough to sound inventive, but the classical root keeps it from feeling arbitrary. The name has the quiet force of a word that has crossed from ritual into identity.