    Sentence 1: It is a contraction of gung-yeh ho-dzo  , ‘industrial cooperation, ‘and it caught on  because it is easy to pronounce, as in 'Nam or the  States . 'Nam by itself is no more derogatory or  misleading than shortening airplane or telephone  ‘or gung-ho .    Sentence 2: It is considered derogatory to  shorten the words airplane and telephone.