[mass noun]behaviour in keeping with good taste and propriety 礼貌;正派得体 ■etiquette 礼仪 he had no idea of funeral decorum. 他对殡葬的礼仪一无所知。 ■[count noun](一般作 decorums)(archaic)a particular requirement of good taste and propriety (古)礼仪要求 ■(archaic)suitability to the requirements of a person, rank, or occasion (古)得体,合宜,相称
语源
mid 16th cent. (as a literary term, denoting suitability of style): from Latin, neuter of the adjective decorus 'seemly'