American Slang & Idioms Starting with "O"

92 entries

Obsessed Extremely into something — loving, being fascinated by, or unable to stop thi...
Obvi A playful abbreviation of 'obviously.'
Ock A friendly term of address, especially used with or by bodega workers and Mid...
OD / Odee Excessively; doing too much; a lot. Short for 'overdoing.'
Off campus Living in private housing outside of university-owned dormitories.
Off the charts So extreme or impressive that it exceeds any normal measurement.
Off the grid Living or traveling without connection to public utilities, cell service, or ...
Off the market No longer single — in a committed relationship and not available for dating.
Off-ramp The exit ramp that leads off a highway or freeway, or figuratively, an exit s...
Off-season The time of year when a tourist destination or outdoor activity has fewer vis...
Office hours Scheduled times when a professor is available in their office to meet with st...
Office politics The informal power dynamics, alliances, and manipulation that happen in a wor...
OG Original gangster. A respected elder or pioneer. Someone who's been around an...
Oh ya An enthusiastic affirmative — distinctly Midwestern.
Oh ya, no, for sure An emphatic agreement stringing together seemingly contradictory words.
Oh, for cute! An exclamation expressing that something is adorable or delightful.
OK, Boomer A dismissive retort to older people perceived as out of touch or condescending.
Old lady One's wife or long-term girlfriend.
Old man One's husband, boyfriend, or father.
Old money A fashion aesthetic inspired by generational wealth — understated luxury, cla...
Old school Classic, traditional, or from an earlier era — used with respect and admiration.
OMG Abbreviation for 'oh my God,' expressing surprise, excitement, or disbelief.
On a break A temporary pause in a relationship where the couple agrees to spend time apa...
On a budget Having limited money to spend; being mindful of expenses.
On another level Far superior to everything else, operating at a completely different standard.
On blast Playing music at full volume, or publicly calling someone out and exposing them.
On brand Consistent with someone's personality, image, or established behavior.
On deck Next in line; ready and waiting for your turn.
On edge Feeling anxious, nervous, or tense, as if something bad might happen.
On fleek Perfectly styled, flawlessly executed, or looking exceptionally good.
On God I swear — used to emphasize that you're being completely truthful or serious.
On my radar Something you are aware of and monitoring, even if not actively working on it.
On one Acting wild, emotional, or irrational — being in an extreme or unpredictable ...
On point Exactly right, perfect, or excellent in every detail.
On repeat Playing a song or show over and over because you love it so much.
On sight Will fight or confront someone immediately upon seeing them. No words needed,...
On ten At maximum intensity, energy, or emotion. Everything turned up to the highest...
On the arm Free of charge; given as a gift or favor, especially food or drinks.
On the back burner Given low priority; postponed to deal with later.
On the clock Currently working or during paid work hours; also means under time pressure.
On the come-up Rising in status, wealth, or success; on the way up.
On the defensive Reacting to attacks or criticism rather than taking initiative; being protect...
On the down low Done secretly or kept quiet; not to be shared with others.
On the flip side On the other hand; from the opposite perspective.
On the front lines At the forefront of an effort; in the most exposed or active position.
On the grind Actively and persistently working hard toward a goal.
On the house Free of charge — paid for by the establishment.
On the lam Fleeing from law enforcement; on the run.
On the low In secret. Discreetly. Keeping something quiet and hidden from others.
On the rebound Starting a new relationship shortly after a breakup, often before fully heali...
On the rocks A drink served over ice cubes.
On the ropes In serious trouble, near defeat, or struggling to survive.
On the run Actively fleeing from law enforcement or other pursuers.
On the same page In agreement or having a shared understanding about something.
On the sidelines Not actively participating; watching from the outside.
On thin ice In a precarious or risky position; close to getting in serious trouble.
On-again, off-again A relationship that repeatedly breaks up and gets back together.
On-ramp The entrance ramp that merges onto a highway or freeway.
Onboarding The process of integrating a new employee or customer into an organization or...
Once in a blue moon A well-known idiom meaning very rarely or almost never, used in all registers.
One for the road A final drink before leaving a bar or party.
One-hit wonder An artist or act known for only a single popular song, never achieving that l...
One-time Police; a warning that police are approaching.
Only in Ohio A meme phrase used to describe bizarre, absurd, or inexplicable events — as i...
OOMF One Of My Followers — used to vaguely reference someone without naming them.
Oorah The battle cry of the US Marine Corps, expressing motivation and esprit de co...
OOTD Acronym for 'Outfit Of The Day' — a social media post showcasing what someone...
Ope A reflexive exclamation used when you accidentally bump into someone or make ...
Open a can of worms To create a complicated situation or bring up a problem that leads to many mo...
Open bar A bar at an event where all drinks are free, usually paid for by the host.
Open door policy A management approach where leaders keep their office door 'open' for anyone ...
Open the kimono To share confidential or internal information with an outside party.
Opening act The first performer at a concert or show, who plays before the main act.
OPSEC Operational Security — keeping sensitive information secret.
Optics How something appears or is perceived by others, especially publicly.
Orbiting When someone stops talking to you directly but continues to engage with your ...
Organic Food produced without synthetic pesticides, fertilizers, or genetic modificat...
Orientation A program for new college students introducing them to campus resources, trad...
Oscar bait A movie that seems specifically designed to win Academy Awards, often featuri...
Oscar Mike On the Move — heading out, currently in transit.
OTP Abbreviation for 'One True Pairing,' referring to your favorite fictional or ...
Out of left field Completely unexpected, surprising, or seemingly random.
Out of my league Someone who is considered too attractive, successful, or desirable for you to...
Out of pocket Acting wild, inappropriate, or out of line — doing or saying something outrag...
Out of this world So amazing that it seems beyond earthly standards.
Out of your league Beyond your level of ability, status, or attractiveness; above your class.
Outer boroughs Brooklyn, Queens, the Bronx, and Staten Island — the four NYC boroughs that a...
Over it Done caring about something, emotionally moved past it, or simply exhausted b...
Over yonder Over there; in that direction, usually referring to a place at some distance.
Overachiever A person who does more than expected or exceeds the standard level of achieve...
Overlanding Self-reliant off-road vehicle travel to remote areas, combining driving and c...
Oy vey An exclamation of dismay, frustration, or exasperation — similar to 'oh no' o...