Lexikon

in chemical engineering an absorber is an equipment in which a gas is absorbed by contact with a liquid.
In electronics, it is a material or device that takes up and dissipates radiated energy; may be used to shield an object from the energy, prevent reflection of the energy, determine the nature of the radiation, or selectively transmit one or more components of the radiation.
The surface on a solar collector that absorbs the solar radiation is also an absorber.
In nuclear technologies absorber is a material that absorbs neutrons or other ionizing radiation.