1. Rain heavily
   "Put on your rain coat— it's pissing down outside!";
   - pour, pelt, rain cats and dogs [informal], rain buckets [informal], belt down [informal], pelt down [informal], bucket [Brit, informal], teem [informal], tip [Brit, informal], chuck it down [Brit, informal], chuck [Brit, informal]

Derived forms: pissed down, pissing down, pisses down

Type of: rain, rain down