The quantity of water, expressed in inches, precipitated as rain, snow, hail, or sleet in a specified area and time interval.
A shower or fall of rain.
The amount of precipitation falling over a given area in a given period of time: it is stated in terms of the depth of water that has fallen into a rain gauge.
The quantity of water, usually expressed in millimeters or inches, that is precipitated in liquid form in a specified area and time interval. Rainfall is often considered to include solid precipitation such as snow, hail, and sleet as well.
(meteorology) The amount of rain that falls on a single occasion.