资料来源 : pyDict

图片描述符  ;   公共域,( PUBLIC DOMAIN 的缩写,指公益软体而言,这类软体的使用是完全免费的)

资料来源 : WordNet®

Pd
     n : 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 [syn: {palladium}, {atomic
         number 46}]

资料来源 : Free On-Line Dictionary of Computing

PD
     
        {public domain}