1. (noun) one part in five equal parts

• fifth part
• one-fifth
• twenty percent

2. (adjective) coming next after the fourth and just before the sixth in position

• 5th

1. (noun) a quantity of liquor equal to one fifth of a United States gallon

• united states liquid unit

2. (noun) position five in a countable series of things

• rank

3. (noun) one part in five equal parts

• common fraction
• simple fraction

4. (noun) the musical interval between one note and another five notes away from it

• interval
• musical interval

1. (adjective) coming next after the fourth and just before the sixth in position

• ordinal

1. (noun) position five in a countable series of things

• 5th