Rain that is red or reddish in colour because of suspended dust or, rarely, green algae containing a red pigment; (in early use also figurative) blood.
Origin
Mid 17th century; earliest use found in Thomas Jordan (c1614–1685), actor, poet, and playwright.
Definition of red rain in US English:
red rain
noun
Rain that is red or reddish in colour because of suspended dust or, rarely, green algae containing a red pigment; (in early use also figurative) blood.
Origin
Mid 17th century; earliest use found in Thomas Jordan (c1614–1685), actor, poet, and playwright.