1 rain /ˈreɪn/ noun
plural rains
1 rain
plural rains
Learner's definition of RAIN
: water that falls in drops from clouds in the sky
see also acid rain
[noncount] : weather in which there is a lot of rain : rainy weather
rains [plural] : large amounts of rain that fall at a particular time of year
[singular] : a large amount of something falling from above

(as) right as rain

see 1right

rain or shine

or come rain, come shine or come rain or come shine
used to say that something will happen even if it rains sometimes used figuratively
2 rain /ˈreɪn/ verb
rains; rained; raining
2 rain
rains; rained; raining
Learner's definition of RAIN
[no object] used with it to say that rain is falling
always followed by an adverb or preposition, [no object] : to fall from above in large amounts
[+ object] : to cause (something) to fall in large amounts

be rained out

(US) or British be rained off
: to be canceled because of rain

rain cats and dogs

: to rain very hard

rain on someone's parade

US, informal
: to spoil someone's pleasure

when it rains, it pours

(US) informal or chiefly British it never rains but it pours
used to say that when something bad happens other bad things usually happen at the same time