To rain very heavily, especially for a long period of time. We were so looking forward to stretching out on the beach in the sunshine, but it poured rain the whole time we were there. It was pouring rain as we drove up to the cemetery for the funeral.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
very heavy rain. The children's clothes were soaked after they played out in the pouring rain. I waited in the pouring rain for the next bus.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.