オ

towel

neon (Ne)

video (esp. a televised image)

radio

orange (fruit, colour)

organ (musical instrument)

stereo (sound)

timidly

script

studio

period (esp. in European languages)

violin

Olympics

champion

opening (a new store, golf course, runway, etc.)

motorcycle

ideology

orchestra

video tape

automation

orchestra

operation

neo

oil

Ottawa (Canada)

ion

opera

chaos

okra (Abelmoschus esculentus)

ozone

otaku

organizer

ounce

trio

viola

bio-

polio

rodeo

(being) on air

ocarina (type of flute)

occult

omelette

oracle

million

ravioli

Ohio

off-the-record

operetta

oasis

onion (Allium cepa)

Orion

Galileo

kiosk

kickoff

neo-Nazi

union

lion (Panthera leo)

(temporary) layoff

opinion

offside

omnibus

oratorio

chameleon

Oklahoma

Oceania

Orient

original

online

Zionist

Zionism

Gregorian (calendar)

con brio

Napoleon

pioneer

pavilion

Oriental

ombudsman

promotional model (at a trade show, etc.)

cohabitation

stereotype

rental video

Orientalism

fellatio

option

quality

Oedipus

office

objet d'art

oil fence

patio

patriotism

violinist

duo

karaoke

auto

aura

all

ogre

oak

ode

overcoat

order

oven

KO

official

oaks

oboe

owner (esp. of a business)

aurora

Oscar

only

quart

theory

hors d'oeuvre

off-road

paper-thin wafer (for wrapping powdered medicine, candies, etc.)

creole

automatic lock

octave

oligomer

music box

diode

play-off

leotard

overrunning (the base)

open-top car

open set

opening

off-season

observer

orthodox

all-night

operator

automatic

overlap

ozone hole

display

creosote

off-season

Belgrade (Serbia)

million seller

made-to-order (esp. clothing)

old guard

orangutan (Pongo pygmaeus)

kinesiology

overheating

all-round

cooling-off (period)

lead-off man

scriptwriter