dampen

bathe, lave

douse (also dowse), drench, impregnate, saturate, soak, souse, steep, wash, water, wet

humidify

dip, dunk, immerge, immerse

flush, irrigate, rinse, sluice

refresh, rehydrate, remoisten

muffle, mute, tone (down)

decrease, diminish, lessen, let up (on), lower, reduce, subdue

debilitate, enfeeble, weaken

dwindle, recede, subside, taper (off), wane

alleviate, ease, lighten

abate, moderate

burn out, debilitate, do in, drain, enfeeble, exhaust, fatigue, sap, tucker (out), undermine, weaken, wear, wear out

daunt, demoralize, discourage, dishearten, dispirit