Rainier \ra(i)-nier\ as a boy's name is a variant of Ragnar (Old Norse), Rainer (Old German) and Raynor (Old German), and the meaning of Rainier is "judgment warrior; deciding warrior".

The baby name Rainier sounds like Raynier, Ranier and Reinier. Other similar baby names are Rainger, Garnier, Gainer, Lanier, Reiner, Rayner, Rainor, Raines, Raine, Ranger, Renier, Raniero, Ranieri, Rayniero and Tanier.