damp

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Slightly wet. See Synonyms at wet.
2. adj. Archaic Dejected.
3. n. Moisture in the air; humidity.
4. n. Foul or poisonous gas that sometimes pollutes the air in coal mines.
5. n. Lowness of spirits; depression.
6. n. A restraint or check; a discouragement.
7. v. To make damp or moist; moisten.
8. v. To extinguish (a fire, for example) by cutting off air.
9. v. To restrain or check; discourage.
10. v. Music To slow or stop the vibrations of (the strings of a keyboard instrument) with a damper.
11. v. Physics To decrease the amplitude of (an oscillating system).
12. damp off Botany To be affected by damping off.

Century Dictionary and Cyclopedia

1. n. Moist air; humidity; moisture.
2. n. A poisonous vapor; specifically, in mining, a stifling or poisonous gas. See black-damp, fire-damp.
3. n. A fog.
4. n. A check; a discouragement.
5. n. Depression of spirits; dejection.
6. Moist; humid; moderately wet: as, a damp cloth; damp air.
7. Clammy.
8. Dejected; depressed.
9. Synonyms Humid, Dank, etc. See moist.
10. To moisten; make humid or moderately wet; dampen.
11. To extinguish; smother; suffocate.
12. To suffocate with damp or foul air in a mine. [Eng.]
13. To check or retard the force or action of: as, to damp a fire by covering it with ashes; especially, to diminish the range or amplitude of vibrations in, as a piano-string, by causing a resistance to the motions of the vibrating body. Both the vibrations and the vibrating body are said to be damped. Usually applied to acoustic vibrations, but also to slower oscillations.
14. To make dull or weak and indistinct, as a sound or a light; obscure; deaden.
15. To depress; deject; discourage; deaden; check; weaken.
16. Specifically To diminish or destroy the oscillation of (a metallic body in motion in a magnetic field). When a conductor is moved in a magnetic field, or when a magnet is moved in the vicinity of a conductor, there will be, in general, an induced current generated which will oppose the motion to which it is due. The moving body will act as if immersed in a viscous liquid, and will more quickly come to rest. Advantage is taken of this fact in stilling the vibrations of a magnetic needle in a galvanometer or a compass by placing masses of conducting metal near the vibrating body. Damping is also accomplished by attaching to the needle a disk, cylinder, or vane, which swings in a liquid or in air.
17. [Dampen is now more common in the literal sense, and is sometimes used in the derived senses.]
18. Synonyms To moderate, allay, dispirit.
19. In horticulture, to rot or waste away, as the stems and leaves of seedlings and other tender plants, when the soil and atmosphere in which they are vegetating are too wet or cold: with off: as, flower-seedlings in hotbeds are especially liable to damp off.
20. n. The popular name of a disease which attacks young seedlings and succulent plants, causing them to rot off near the surface of the ground. An excessively moist atmosphere is particularly favorable for its development, Pythium De Baryanum is responsible for most of the “damp” in cucumbers, egg-plants, peas and similar plants while a species of Rhizoctonia causes this disease in cotton, and Alternaria, tennis produces the effect in tobacco. Also called damping off.

Wiktionary

1. adj. Being in a state between dry and wet; moderately wet; moist.
2. adj. obsolete Pertaining to or affected by noxious vapours; dejected, stupified.
3. n. Moisture; humidity; dampness.
4. n. archaic Fog; fogginess; vapor.
5. n. archaic Dejection or depression.
6. n. archaic, mining A gaseous product, formed in coal mines, old wells, pits, etc.
7. v. transitive, archaic To dampen; to render damp; to moisten; to make humid, or moderately wet; as, to damp cloth.
8. v. transitive, archaic To put out, as fire; to depress or deject; to deaden; to cloud; to check or restrain, as action or vigor; to make dull; to weaken; to discourage.
9. v. transitive To suppress vibrations (mechanical) or oscillations (electrical) by converting energy to heat (or some other form of energy).

GNU Webster's 1913

1. n. Moisture; humidity; fog; fogginess; vapor.
2. n. Dejection; depression; cloud of the mind.
3. n. (Mining) A gaseous product, formed in coal mines, old wells, pints, etc.
4. adj. Being in a state between dry and wet; moderately wet; moist; humid.
5. adj. rare Dejected; depressed; sunk.
6. v. To render damp; to moisten; to make humid, or moderately wet; to dampen.
7. v. To put out, as fire; to depress or deject; to deaden; to cloud; to check or restrain, as action or vigor; to make dull; to weaken; to discourage.

WordNet 3.0

1. v. deaden (a sound or noise), especially by wrapping
2. v. make vague or obscure or make (an image) less visible
3. v. lessen in force or effect
4. n. a slight wetness
5. v. restrain or discourage
6. adj. slightly wet