Answer: sextodecimo

AnswerCrossword Clue
sextodecimoa book size 55/8 x 43/8 in. (abbreviated as 16mo.) also SIXTEENMO
sextodecimoprinted, folded, or bound in sixteenmo; sextodecimo
sextodecimobook size (about 4x6 in.; 10x15 cm) determined by printing on sheets folded to form 16 leaves or 32 pages