post octavo

11 LETTERS · STARTS WITH P

post octavo is a valid 11-letter word worth 17 points in Scrabble and 20 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3O1S1T1O1C3T1A1V4O1

3 + 1 + 1 + 1 + 0 + 1 + 3 + 1 + 1 + 4 + 1 =17 PTS

DOUBLE WORD → 34TRIPLE WORD → 51

MEANING

What does post octavo mean?