词典释义：
constituting number five in a sequence; 5th
第五
-
the fifth century BC 公元前５世纪
-
her mother had just given birth to another child, her fifth 她妈妈刚才又生了一个孩子，她的第五个孩子
-
the world's fifth-largest oil exporter 世界第五大石油出口商
-
the fifth of November .１１月５号。
(
五分之一。
the fifth finisher or position in a race or competition
（比赛或竞赛的）第五名；第五位
-
he finished fifth .他得了第五名。
(in some vehicles)the fifth (and typically highest) in a sequence of gears
（某些机动车辆的）第五挡（通常为最高挡）
-
in my panic I changed from third to fifth .慌乱之中，我从第三档换到了第五档。
〈主英〉 （学校、学院的）五年级。
fifthly (used to introduce a fifth point or reason)
第五（用来引出第五个要点或原因）
-
fourth, it can aid the process of life review, and fifth, it is an enjoyable and stimulating experience .第四，它有助于回顾生活的历程，第五，这种经历让人感到愉悦、刺激。
【乐】 五度音程
-
strings tuned a fifth apart .把五度音程彼此定开的弦。
【乐】 五度和音。
(
〈美，非正式〉 （酒的计量单位）五分之一加仑；五分之一加仑的酒瓶
-
a fifth of whisky .１／５加仑的威士忌。
-
take the fifth （in the US） exercise the right guaranteed by the Fifth Amendment to the Constitution of refusing to answer questions in order to avoid incriminating oneself （美国）（根据《美国宪法第五修正案》）行使拒绝回答问题的权利（以免使自己显得有罪）
