1.第5，第五（个）
n.
1.五分之一 词形变化
- 副词 fifthly
- coming next after the fourth and just before the sixth in position
- one part in five equal parts
- position five in a countable series of things
- the musical interval between one note and another five notes away from it
- a quantity of liquor equal to one fifth of a United States gallon