O — oa ob oc od oe of og oh oi ok ol om on oo op or os ot ou ov ow ox oy oz
on |ɑːn| — in operation or operational
on-board |ˈɑːnˌbɔːrd| — (idiomatic) On or in a means of transportation.
on-license — a license to sell liquor for consumption on the premises
on-line |ˈɒnˌlaɪn| — being in progress now
on-screen |ˈɔːnˈskrɪn| — As seen on a screen (as of television, film, or computer) rather than in real life.
on-site |ˈɑːnˈsaɪt| — taking place or located at the site
on-the-job |ˌɒn ðə ˈdʒɒb| — relating to or associated with a job or employment
on-the-spot — at the scene of action
onager |ˈɑːnədʒər| — an engine that provided medieval artillery used during sieges; a heavy war engine for hurling large stones and other missiles
onagri |ˈɒnəɡraɪ| — plural form of onager
onanism |ˈəʊnənɪzəm| — manual stimulation of the genital organs (of yourself or another) for sexual pleasure
onboard |ˈɑːnˌbɔːrd| — Carried or used on or in a vehicle or vessel
once |wʌns| — on one occasion
once-over |ˈwʌnsˌəʊvə| — a swift cursory examination or inspection
oncer |ˈwʌnsər| — (informal, historical) A one-pound note.
oncological |ˌɒnkəˈlɒdʒɪkəl| — of or relating to or practicing oncology
oncologist |ɑːnˈkɑːlədʒɪst| — a specialist in oncology
oncology |ɑnˈkɑːlədʒɪ| — the branch of medicine concerned with the study and treatment of tumors
oncoming |ˈɑːnkʌmɪŋ| — the beginning or early stages
ondatra |ɒnˈdætrə| — muskrats
one |wʌn| — the smallest whole number or a numeral representing this number
one-armed |ˌwʌn ˈɑːrmd| — having one arm
one-dimensional |ˌwʌndaɪˈmenʃənəl| — relating to a single dimension or aspect; having no depth or scope
one-eyed |ˌwʌn ˈaɪd| — having or showing only one eye
one-fifth — one part in five equal parts
one-fourth — one of four equal parts
one-half — one of two equal parts of a divisible whole
one-handed |ˈwʌnˌhændɪd| — having or using a single hand
one-horse |ˌwʌn ˈhɔːrs| — small and remote and insignificant
one-legged |ˈwʌnˈleɡd| — Having only one leg.
one-liner |ˌwʌnˈlaɪnər| — a one-line joke
one-man |ˈwən ˌman| — designed for or restricted to a single person
one-off |wʌnˈɒf| — a happening that occurs only once and is not repeated
one-on-one |ˈwʌn ɔːn ˈwʌn| — (of two persons) in direct encounter
one-party — determined by a single party
one-piece |ˈwʌnˈpiːs| — (of clothing) consisting of or fashioned in a single whole piece
one-quarter — one of four equal parts
one-sided |ˌwʌnˈsaɪdɪd| — favoring one person or side over another
one-sixth — one part in six equal parts
one-stop |ˈwʌnstɒp| — (management) Describing a service operation at which all of a customer's needs may be satisfied without visiting another.
one-tenth — a tenth part; one part in ten equal parts
one-third — one of three equal parts of a divisible whole
one-time |ˈwʌntaɪm| — belonging to some prior time
one-to-one |wʌntəˈwʌn| — used of relations such that each member of one set is associated with one member of a second set
one-track |ˈwʌnˈtræk| — (of a railway) having a single set of lines so that trains can run only in one direction at a time; single-track
one-up — (idiomatic) To outdo, to do something slightly better than a competitor's prior effort.
one-upmanship |wʌn ˈʌpmənʃɪp| — the practice of keeping one jump ahead of a friend or competitor
one-way |ˌwʌnˈweɪ| — moving or permitting movement in one direction only
one-year |ˈwəˈnjɪr| — completing its life cycle within a year
onefold |ˈwʌnfəʊld| — Constituting or being indicative of a single aspect or theme.
oneness |ˈwʌnnəs| — the quality of being united into one
oner |ˈwənər| — (informal) An extraordinary individual.
onerous |ˈɑːnərəs| — not easily borne; wearing
onerously |ˈəʊnərəslɪ| — in an onerous manner
oneself |wʌnˈself| — The person, previously mentioned.
onetime |ˈwʌntaɪm| — belonging to some prior time
onfall |ˈɑːnfɑːl| — A falling on or upon; an attack, onset, or assault.
ongoing |ˈɑːnɡəʊɪŋ| — currently happening
ongoings |ˈɒnˌɡəʊɪŋz| — plural form of ongoing
onhanger |ˈɒnˌhæŋə| — That which, or one who, hangs on to, relies on, or is dependent upon another; a dependant.
onion |ˈʌnjən| — the bulb of an onion plant
onionskin |ˈʌnjənˌskɪn| — a thin strong lightweight translucent paper used especially for making carbon copies
oniony |ˈʌnjənɪ| — Resembling an onion or onions, especially in terms of smell.
online |ˌɑːnˈlaɪn| — being in progress now
onlooker |ˈɑːnlʊkər| — someone who looks on
onlooking — That is looking on; watching, observing.
only |ˈəʊnlɪ| — and nothing more
onomastic |ˌɑːnəˈmæstɪk| — of or related to onomastics
onomatopoeia |ˌɑːnəˌmætəˈpiːə| — using words that imitate the sound they denote
onomatopoeic |ˌɑːnəˌmætəˈpiːɪk| — of or relating to or characterized by onomatopoeia
onomatopoeical |ˌɒnəʊmətəʊˈpiːɪkəl| — (of words) formed in imitation of a natural sound
onrush |ˈɑːnrʌʃ| — (military) an offensive against an enemy (using weapons)
onset |ˈɑːnset| — the beginning or early stages
onside |ˌɑːnˈsaɪd| — not offside; being within the prescribed area of play
onslaught |ˈɑːnslɔːt| — a sudden and severe onset of trouble
onstage |ˌɑːnˈsteɪdʒ| — situated or taking place on the area of a stage visible to the audience
onto |ˈɑːntə| — Upon; on top of.
ontogenesis |ˌɑːntəˈdʒenɪsɪs| — (biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level
ontogeny |anˈtɑːdʒənɪ| — (biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level
ontological |ˌɑːntəˈlɑːdʒɪkl| — of or relating to ontology
ontology |ɑːnˈtɑːlədʒɪ| — (computer science) a rigorous and exhaustive organization of some knowledge domain that is usually hierarchical and contains all the relevant entities and their relations
onus |ˈəʊnəs| — an onerous or difficult concern
onward |ˈɑːnwərd| — forward in time or order or degree
onwards |ˈɑːnwərdz| — in a forward direction
onyx |ˈɑːnɪks| — a chalcedony with alternating black and white bands; used in making cameos