Dictionary entry

Octavo

Webster's Dictionary 1913

Oc‐ta″vo (?), n.;pl.Octavos (#). [L. in octavo; in in + octavo, abl. of octavus. See Octave.] A book composed of sheets each of which is folded into eight leaves; hence, indicating more or less definitely a size of book so made; — usually written 8vo or 8°.