Answer: sextodecimos

AnswerCrossword Clue
sextodecimosA book of this size
sextodecimosSEXTODECIMO, a book size 55/8 x 43/8 in. (abbreviated as 16mo.) also SIXTEENMO
sextodecimosA size of book page that results from folding each printed sheet into sixteen leaves (thirty-two pages)