damper

noun

1. a movable iron plate that regulates the draft in a stove or chimney or furnace

   noun.artifact

   Source: WordNet 3.0

2. a device that decreases the amplitude of electronic, mechanical, acoustical, or aerodynamic oscillations

   noun.artifact

   Synonyms muffler

   Source: WordNet 3.0

3. a depressing restraint

   noun.act

   Examples

   Rain put a damper on our picnic plans.

   Source: WordNet 3.0

4. That which damps or checks; as: <sd><i>(a)</i></sd> A valve or movable plate in the flue or other part of a stove, furnace, etc., used to check or regulate the draught of air. <sd><i>(b)</i></sd> A contrivance, as in a pianoforte, to deaden vibrations; or, as in other pieces of mechanism, to check some action at a particular time.

   noun

   Source: webster1913