next after the fourth; being the ordinal number for five.

being one of five equal parts.

Automotive . of, pertaining to, or operating at the gear transmission ratio at which the drive shaft speed is greater than that of fourth gear for a given engine crankshaft speed

fifth gear.

in the fifth place; fifthly.

a fifth part, esp. of one ( 1 / 5 ).

the fifth member of a series.

a fifth part of a gallon of liquor or spirits; 4 / 5 of a quart (about 750 milliliters).

Automotive . fifth gear.

Music .

a tone on the fifth degree from another tone (counted as the first).

the interval between such tones.

the harmonic combination of such tones. ?

take the Fifth

Informal . to decline on the basis of the Fifth Amendment to the U.S. Constitution to answer a question when testifying.

adjective

quinary , quinquennial , quintan

noun

quinquennial