Webster’s Revised Unabridged Dictionary · 1913
Dampen
Damp′en (dămp′'n), v. t. [imp. & p. p. Dampened; p. pr. & vb. n. Dampening.] 1. To make damp or moist; to make slightly wet.
2. To depress; to check; to make dull; to lessen.
In a way that considerably dampened our enthusiasm. The Century.
Damp′en, v. i. To become damp; to deaden. Byron.