sixth

Etymology

From earlier sixt, from Middle English sixte, from Old English siexta, from Proto-Germanic *sehstô.

adj

1. The ordinal form of the number six.
   Transliterated: And God saw everything that he had made: and behold, it was very good. And the evening and the morning were the sixth day.
   Dr. Ridpath, in his usual happy manner, thanked the Executive Committee and the various members of the Association who had so earnestly cooperated with him in the work of the Sixth Annual Meeting now drawing to a close. 1892, Western Association of Writers, Sayings and Doings of the Sixth General Meeting, Jones Brothers Publishing Company, pages 271–272
   As this sixth edition is published in 2011, it is exactly 25 years since the publication of the first edition in 1986. That, in itself, is a very sobering thought, for all kinds of reasons. 25 February 2011, Peter Dicken, Global Shift, Sixth Edition: Mapping the Changing Contours of the World Economy, Guilford Press, page xi

noun

1. (not used in the plural) The person or thing in the sixth position.
2. One of six equal parts of a whole.
3. (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. (Note that the interval covers six notes counting inclusively, for example C-D-E-F-G-A.)

verb

1. to divide by six, which also means multiplying a denominator by six
   Why would anyone use sixthing when any (N − a²) divisible by 6 would also be divisible by 3? The answer is that sometimes the numerator and/or the denominator is simpler in sixthing, 1993, Dead Reckoning: Calculating Without Instruments, page 102