damp 
(dămp)
(dămp)adj. damp·er, damp·est
1. Slightly wet: a damp sponge.
2. Humid: damp air.
3. Archaic Dejected; depressed.
n.
1.
a. Moisture in the air; humidity: Come in out of the damp.
b. Moisture that lies or has condensed on something: "I saw the damp lying on the bare hedges and spare grass" (Charles Dickens).
2. Foul or poisonous gas that sometimes pollutes the air in coal mines.
3. Archaic
a. Lowness of spirits; depression: "An angry or sorrowful [countenance] throws a sudden damp upon me" (David Hume).
b. A restraint or check; a discouragement: "The issue of arms was so slow as to throw a great damp upon volunteering" (James Franck Bright).
tr.v. damped, damp·ing, damps
Phrasal Verb: 1. To make damp or moist; moisten.
2. To suppress or extinguish (a fire) by reducing or cutting off air.
3. To restrain or check; discourage: news that damped our enthusiasm.
4. Music To slow or stop the vibrations of (the strings of a keyboard instrument) with a damper.
5. Physics To decrease the amplitude of (an oscillating system).
damp off Botany
To be affected by damping off.
[Middle English, poison gas, perhaps from Middle Dutch, vapor.]
dampish adj.
damply adv.
dampness n.