1. To rise as vapor.
2. To emit steam
3. To cook something by letting steam pass over it
4. To clean by means of steaming; SYN. steam clean.
5. To travel on a steamboat

ETYM Old Eng. stem, steem, vapor, flame, AS. steám vapor, smoke, odor; akin to Dutch stoom steam, perhaps originally, a pillar, or something rising like a pillar.
Water at boiling temperature diffused in the atmosphere.
In chemistry, a dry, invisible gas formed by vaporizing water.
The visible cloud that normally forms in the air when water is vaporized is due to minute suspended water particles. Steam is widely used in chemical and other industrial processes and for the generation of power.