(physics) material in a nuclear reactor that absorbs radiation
"The engineer adjusted the control rods to increase the neutron absorber's density and stabilize the reactor core."
Something that absorbs.
"The new soundproofing material acts as an excellent absorber for the echoey noises in the large hall."
A device which causes gas or vapor to be absorbed by a liquid.
"The engineer selected a specialized chemical absorber to remove sulfur dioxide from the industrial exhaust stream before it reached the atmosphere."
The word comes from the verb absorb with the suffix -er. It originally meant one who or that which performs the action of absorbing.