OA (30 words)
Oad to Oatmeal

OB (269 words)
Ob to Oby

OC (157 words)
Ocarina to Ocypodian

OD (59 words)
Od to Odyssey

OE (31 words)
OElig to Oersted

OF (90 words)
Of to Ofttimes

OG (15 words)
Ogam to Ogygian

OH (5 words)
Oh to Oho

OI (30 words)
Oil to Ointment

OJ (1 word)
Ojibways to Ojibways

OK (9 words)
okapi to Okra

OL (108 words)
Old to Olympus

OM (81 words)
Omahas to Omy

ON (124 words)
On to Onyx

OO (31 words)
Oo to Oozy

OP (244 words)
Opacate to Opye

OQ (1 word)
Oquassa to Oquassa

OR (389 words)
Or to orzo

OS (149 words)
Os to Oswego tea

OT (48 words)
otacoustic to Ottrelite

OU (342 words)
Ouananiche to Ouzel

OV (562 words)
Oval to Ovulite

OW (27 words)
Owch to Owse

OX (117 words)
Ox to Oxytonical

OY (9 words)
Oyer to Oysterling

OZ (16 words)
ozena to ozonous