Definition of sixths:
(adj) :
The ordinal form of the number six.
(n) :
(not used in the plural) The person or thing in the sixth position.
(n) :
One of six equal parts of a whole.
(n) :
(music) The interval between one note and another, five notes higher in the scale; for example C to A, a major sixth, or C to A flat, a minor sixth.
(v) :
(informal, nonstandard, rare) To divide by six, equivalent to multiplying a denominator by six.