absorbent

Short definition from Wiktionary

Adjective

1. 1
   Having the ability or tendency to absorb; able to soak up liquid easily; absorptive.

Noun

1. 1
   Anything which absorbs.
2. 2
   The vessels by which the processes of absorption are carried on, as the lymphatics in animals, the extremities of the roots in plants.
3. 3
   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.
4. 4
   A liquid used in the process of separating gases or volatile liquids, in oil refining.