Damp
Middle English (in the noun sense ‘noxious inhalation’): of West Germanic origin; related to a Middle Low German word meaning ‘vapour, steam, smoke’.
wiktionary
From Middle English dampen(“to stifle; suffocate”). Akin to Low German damp, Dutch damp, and German Dampf(“vapor, steam, fog”), Icelandic dampi, Swedish damm(“dust”), and to German dampf imperative of dimpfen(“to smoke”). Also Middle English dampen(“to extinguish, choke, suffocate”). Ultimately all descend from Proto-Germanic *dampaz.
etymonline
damp (n.)
early 14c., "noxious vapor in a coal mine, fire-damp, stifling poisonous gas," perhaps in Old English but there is no record of it. If not, probably from Middle Low German damp; ultimately in either case from Proto-Germanic *dampaz (source also of Old High German damph, German Dampf "vapor;" Old Norse dampi "dust"). Sense of "moist air, moisture, humidity" is not easily distinguished from the older sense but is certainly attested by 1706.
damp (v.)
late 14c., "to suffocate" (with or as with damp, foul air in a mine), from damp (n.). Figurative meaning "to check or retard the force or action of (the spirits, etc.)" is attested by 1540s. Meaning "to moisten" is recorded from 1670s. Century Dictionary (1897) states that "Dampen is now more common in the literal sense, and is sometimes used in the derived senses." Related: Damped; damping.
damp (adj.)
1580s, "dazed," from damp (n.). Meaning "slightly wet" is from 1706. Related: Damply; dampness.
