verb (used without object), sub·sid·ed, sub·sid·ing. to sink to a low or lower level. to become quiet, less active, or less violent; abate: The laughter subsided.

Is the word subsided an adjective?

Subside is a verb. ... See the conjugation of the verb subside in English.

What is the noun for subside?

subsidence. The process of becoming less active or severe. (geology) A sinking of something to a lower level, especially of part of the surface of the Earth due to underground excavation or seismic activity or groundwater depletion.