Pd fairly common us noun 1. a silver-white metallic element of the platinum group that resembles platinum; occurs in some copper and nickel ores; does not tarnish at ordinary temperatures and is used (alloyed with gold) in jewelry Synonymspalladiumatomic number 46 Related words Broader terms metallic element WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.