13-letter words starting with o
- octagon scale — a scale used in laying out octagonal figures of various sizes.
- octane number — (of gasoline) a designation of antiknock quality, numerically equal to the percentage of isooctane by volume in a mixture of isooctane and normal heptane that matches the given gasoline in antiknock characteristics.
- octane-rating — (of gasoline) a designation of antiknock quality, numerically equal to the percentage of isooctane by volume in a mixture of isooctane and normal heptane that matches the given gasoline in antiknock characteristics.
- octanoic acid — caprylic acid.
- octocentenary — pertaining to 800 or a period of 800 years; marking the completion of 800 years.
- octodecillion — a cardinal number represented in the U.S. by 1 followed by 57 zeros, and in Great Britain by 1 followed by 108 zeros.
- octogenarians — Plural form of octogenarian.
- octosyllables — Plural form of octosyllable.
- octyl alcohol — any of a group of isomers having the formula C 8 H 1 8 O, especially used in making perfumes and as a solvent.
- odds and ends — miscellaneous items, matters, etc.
- odds and sods — small miscellaneous items
- odontoblastic — Relating to odontoblasts.
- odontogenesis — the development of teeth.
- odontoglossum — any epiphytic orchid of the genus Odontoglossum, of the mountainous regions from Bolivia to Mexico.
- odontornithes — a proposed class of birds that possess teeth
- odoriferously — In an odoriferous manner.
- oeil-de-boeuf — a comparatively small round or oval window, as in a frieze.
- of a lifetime — unique and special
- of all others — above all others
- of many parts — having many different abilities
- of many words — talkative
- of one's word — given to or noted for keeping one's promises
- of the moment — You use of the moment to describe someone or something that is or was especially popular at a particular time, especially when you want to suggest that their popularity is unlikely to last long or did not last long.
- off one's nut — a dry fruit consisting of an edible kernel or meat enclosed in a woody or leathery shell.
- off soundings — in waters more than 100 fathoms in depth
- off the books — of or relating to a book or books: the book department; a book salesman.
- off the chain — wildly entertaining
- off the rails — into or in a state of dysfunction or disorder
- off the shelf — readily available from merchandise in stock.
- off the track — a structure consisting of a pair of parallel lines of rails with their crossties, on which a railroad train, trolley, or the like runs.
- off the wagon — any of various kinds of four-wheeled vehicles designed to be pulled or having its own motor and ranging from a child's toy to a commercial vehicle for the transport of heavy loads, delivery, etc.
- off with you! — go away! depart!
- off-side rule — A lexical convention due to Landin, allowing the scope of declarations in a program to be expressed by indentation. Any non-whitespace token to the left of the first such token on the previous line is taken to be the start of a new declaration. Used in, for example, Miranda and Haskell.
- off-the-books — not recorded in account books or not reported as taxable income.
- off-the-shelf — readily available from merchandise in stock.
- offensiveness — causing resentful displeasure; highly irritating, angering, or annoying: offensive television commercials.
- offertory box — the box or container where worshippers' put their offerings (usually money)
- offhandedness — cavalierly, curtly, or brusquely: to reply offhand.
- office bearer — a person who holds an office, as in a society, company, club, etc; official
- office junior — a young person, esp a school-leaver, employed in an office for running errands and doing other minor jobs
- office seeker — a person who seeks appointment or election to some government position.
- office worker — employee in an office
- office-holder — An office-holder is a person who has an important official position in an organization or government.
- officeholders — Plural form of officeholder.
- officiousness — objectionably aggressive in offering one's unrequested and unwanted services, help, or advice; meddlesome: an officious person.
- offshore dock — a floating dock moored to pilings, dolphins, etc., used for cleaning and repairing medium-sized vessels.
- oil hardening — to quench (steel) in a bath of oil.
- oil pollution — pollution caused by the leaking of oil, esp. from a ship
- oil-based mud — Oil-based mud is a drilling fluid that is an emulsion containing oil as the base fluid.
- oilspot glaze — a brown or black ceramic glaze dotted with silvery spots caused by impurities.