Roamer:

A roamer is a hero role that moves around the map to create pressure in different lanes rather than staying in one fixed lane. Roamers look for kills, set up ganks, place vision, and help teammates win side lanes or control key areas of the map.

In Dota 2, the term is often used for support heroes that rotate early and frequently. A good roamer can disrupt the enemy’s farm, protect allies, and open space for cores to scale.

Related: Support, Gank, Vision