Inflected forms: pl. sex·to·dec·i·mos 1. The page size of a book composed of printer's sheets folded into 16 leaves or 32 pages. 2. A book composed of sextodecimo pages. In both senses also called sixteenmo.
ETYMOLOGY:
Latin sextdecim, ablative of sextusdecimus, one sixteenth : sextus, sixth; see s(w)eks in Appendix I + decimus, tenth (from decem, ten; see dek in Appendix I).