the.com/dampen
To take the enthusiasm out of something, one drop at a time.
means To make slightly wet, or to lessen the force, intensity, or spirit of something.
from From 'damp,' once meaning a noxious vapor or fog in mines — the kind that smothered flames and lungs alike, hence 'to deaden.'
Old menace'Damp' meant suffocating gas before it meant moisture.
Two jobsWets your towel, kills your mood, deadens your guitar string.
Spirit-crusher'Dampen spirits' keeps the original smothering sense alive.