agent

Agent comes from Latin agēns, the present active participle of agere, meaning 'to drive, lead, conduct, manage, perform, do.' That verb traces back through Proto-Italic agō to the Proto-Indo-European root *h₂eǵ-, meaning to drive or lead.

The word entered English carrying the sense of its Latin participle — literally 'one who is doing' — and that core idea of an active doer has stayed remarkably intact.

Because agent comes from the same verb agere that gives Latin its family of 'doing' and 'driving' words, it shares a root with other English words built on that stem, though the facts here don't name them specifically.