The process of producing a separable solid phase within a liquid medium; represents the formation of a new condensed phase, such as a vapor or gas condensing to liquid droplets; a new solid phase gradually precipitates within a solid alloy as a result of slow, inner chemical reaction; in analytical chemistry, precipitation is used to separate a solid phase in an aqueous solution.

Aggregation of soluble antigen by an antibody.

1. Any or all of the forms of water particles, whether liquid or solid, that fall from the atmosphere and reach the ground.

2. The amount, usually expressed in inches of liquid water depth, of the water substance that has fallen at a given point over a specified period of time.