absorbent

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Capable of absorbing a liquid or gas.
• noun A substance that is capable of absorbing.

from The Century Dictionary.

• Absorbing or capable of absorbing; imbibing; swallowing; performing the function of absorption: as, absorbent vessels; the absorbent system.
• noun Anything which absorbs.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Absorbing; swallowing; absorptive.
• adjective (Paint.) a ground prepared for a picture, chiefly with distemper, or water colors, by which the oil is absorbed, and a brilliancy is imparted to the colors.
• noun Anything which absorbs.
• noun (Med.) Any substance which absorbs and neutralizes acid fluid in the stomach and bowels, as magnesia, chalk, etc.; also a substance e. g., iodine) which acts on the absorbent vessels so as to reduce enlarged and indurated parts.
• noun (Physiol.) The vessels by which the processes of absorption are carried on, as the lymphatics in animals, the extremities of the roots in plants.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun medicine Any substance which absorbs and neutralizes acid fluid in the stomach and bowels, as magnesia, chalk, etc.; also a substance, e.g., iodine, which acts on the absorbent vessels so as to reduce enlarged and indurated parts.
• noun chemistry A liquid used in the process of separating gases or volatile liquids, in oil refining.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective having power or capacity or tendency to absorb or soak up something (liquids or energy etc.)
• noun a material having capacity or tendency to absorb another substance