English–Korean dictionary: O
- o'clock
- ob-gyn
- obesity
- object
- objection
- objective
- observation
- observation deck
- observe
- obsession
- obvious
- occur
- occurrence
- ocean view
- october
- odd number
- of all people
- of course
- off-season
- off-site work
- off the mark
- offer
- office
- office job
- office work
- office worker
- official
- official date stamp
- offline
- often
- oh
- oh dear
- oh man
- oh my
- oh my gosh
- oil
- ointment
- okay
- old
- old days
- old palace
- old story
- older brother
- older generation
- older person
- older sister
- oldest child
- olympics
- omission
- on
- on campus
- on earth
- on foot
- on purpose
- on-site payment
- on-site registration
- on-site sales
- on the other hand
- on the phone
- on the way
- on time
- once
- one
- one by one
- one day
- one hundred thousand
- one hundred twelve
- one night
- one-night stay
- one or two
- one's heart's content
- one's own handwriting
- one's own signature
- one serving
- one side
- one size
- one-time password
- one-way
- one-way traffic
- one week
- oneself
- onion
- online
- online banking
- online booking
- online payment
- online store
- only
- only child
- only son
- only then
- open
- open one's eyes
- open up
- opening
- opening remarks
- opening time
- opera
- operating room
- operating table
- operation
- opinion
- opportunity
- oppose
- opposite
- opposite sex
- opposite side
- opposition
- opt-out
- optimistic
- option
- or
- orange
- order
- order history
- order number
- ordinary
- ordinary people
- ordinary person
- organization
- organizational structure
- organizer
- origin
- original
- original place
- originally
- originate from
- orthopedic clinic
- other
- other person
- other side
- other way around
- otherwise
- our bank
- our country
- out of breath
- out-of-pocket cost
- out of service
- out of town
- outbox
- outdoor seating
- outdoors
- outer fabric
- outerwear
- outfit
- outgoing
- outing
- outlet
- outline
- outpatient care
- outside
- outside the door
- outside the window
- outskirts
- oven
- over-the-counter medicine
- over there
- overage charge
- overall
- overcome
- overcoming
- overdo it
- overdose
- overdraft account
- overeating
- overflow
- overlap
- overnight stay
- overseas korean
- oversleeping
- overspending
- overtime
- overwhelming
- overwork
- own
- owner
- ownership
- ox-bone soup
- oxygen
- oxygen mask
- oyster