noun

1. a gas, smoke, or vapor, esp. if offensive or suffocating
2. anything imaginary or without substance
3. Rare anything that weakens clear thinking
4. Rare an outburst of anger, annoyance, etc.
5. Chem. a number of solid or liquid particles within a gas

Etymology: ME < OFr fum < L fumus < IE base *dheu-, to blow, smoke, be turbid > dull

intransitive verb fumed, fuming fum′·ing

1. to give off gas, smoke, or vapor
2. to rise up or pass off in fumes
3. to show, or give way to, anger, annoyance, etc.

Etymology: ME fumen < OFr fumer < L fumare < fumus

transitive verb

1. to expose to fumes
2. to give off as fumes