Zoology. one of the slender, sharp stylets embedded in the parapodia of certain annelid worms, as the polychaetes.
noun (pl) -lums, -la (-lə)
a needle-like bristle that provides internal support for the appendages (chaetae) of some polychaete worms
- Acid anhydride
See under (def 1). a compound formed by removing water from a more complex compound: an oxide of a nonmetal (acid anhydride) or a metal (basic anhydride) that forms an acid or a base, respectively, when united with water. a compound from which water has been abstracted. Historical Examples Like most of the oxides of […]
Chemistry. a compound usually having a sour taste and capable of neutralizing alkalis and reddening blue litmus paper, containing hydrogen that can be replaced by a metal or an electropositive group to form a salt, or containing an atom that can accept a pair of electrons from a base. Acids are proton donors that yield […]
- Acid cell
Electricity. a cell using an acid electrolyte. . acid cell n. See parietal cell.
- Acid deposition
acid deposition acid deposition The accumulation of acids or acidic compounds on the surface of the Earth, in lakes or streams, or on objects or vegetation near the Earth’s surface, as a result of their separation from the atmosphere. Acid deposition can harm the environment in a variety of ways, as by causing the acidification […]