1. n. 
A chemical with formula Ca(OH)2, commonly called slaked lime. Lime is used in lime muds and as a treatment to remove carbonate ions. It is used as a stabilizing ingredient in oil- and synthetic-based mud, essential to formation of fatty-acid soap emulsifiers. It is an alkaline material that can be carried in excess to neutralize hydrogen sulfide [H2S] and carbon dioxide [CO2].
Alternate Form: slaked lime