13-letter words containing t, r, o, i, s
- nonpractising — of or relating to a person who no longer observes or pursues his or her religious faith
- nonresistance — the policy or practice of not resisting violence or established authority, even when tyrannical, by force.
- nonrestricted — confined; limited.
- nonstationary — Not stationary.
- nontransitive — Grammar. having the nature of a transitive verb.
- nonuniversity — distinct from university, not university-based
- normalisation — Alternative form of normalization.
- normativeness — The quality or state of being normative.
- normotensives — Plural form of normotensive.
- north ossetia — an autonomous republic in S European Russia, in the N Caucasus. 3100 sq. mi. (8029 sq. km) Capital: Vladikavkaz.
- north sea oil — oil extracted from deposits beneath the North Sea
- northerliness — The quality of being northerly.
- notoriousness — publicly or generally known, as for a particular trait: a newspaper that is notorious for its sensationalism. Synonyms: notable, renowned, celebrated, prominent, conspicuous, famous, widely known.
- numerologists — the study of numbers, as the figures designating the year of one's birth, to determine their supposed influence on one's life, future, etc.
- nutrigenomics — the study of how individual genetic makeup interacts with diet, especially the effects of this interaction on a person's health.
- nutritionists — Plural form of nutritionist.
- o-proposition — a particular negative proposition
- observability — capable of being or liable to be observed; noticeable; visible; discernible: an observable change in attitude.
- observational — of, relating to, or founded on observation, especially founded on observation rather than experiment.
- observatories — Plural form of observatory.
- obstetrically — (medicine) In terms of obstetrics.
- obstetricians — Plural form of obstetrician.
- obstructively — In an obstructive manner.
- obtrusiveness — having or showing a disposition to obtrude, as by imposing oneself or one's opinions on others.
- oceanic crust — the brown, hard outer portion or surface of a loaf or slice of bread (distinguished from crumb).
- octogenarians — Plural form of octogenarian.
- odontornithes — a proposed class of birds that possess teeth
- off the rails — into or in a state of dysfunction or disorder
- old ritualist — Raskolnik.
- omnipresently — In an omnipresent manner.
- on its merits — on the intrinsic qualities or virtues
- on the parish — receiving parochial relief
- one's forties — the ages between 40 and 49
- oneiroscopist — a person who specialises in studying and interpreting dreams
- open registry — ship registration under a national flag available to all ships regardless of nationality.
- operativeness — (uncountable) The state or quality of being operative.
- opisthobranch — any gastropod mollusk of the order Opisthobranchia, as the sea slugs, sea butterflies, and sea hares, characterized by a vestigial or absent mantle and shell and two pairs of tentacles.
- opisthography — the practice of writing on the front and back of a parchment or papyrus
- opportunistic — adhering to a policy of opportunism; practicing opportunism.
- opportunities — Plural form of opportunity.
- oppositionary — the action of opposing, resisting, or combating.
- oral solution — An oral solution is a medicine in liquid form for drinking.
- orchestra pit — musicians' seating in front of stage
- orchestra-pit — a group of performers on various musical instruments, including especially stringed instruments of the viol class, clarinets and flutes, cornets and trombones, drums, and cymbals, for playing music, as symphonies, operas, popular music, or other compositions.
- orchestralist — a person who writes or arranges orchestral music
- orchestrating — Present participle of orchestrate.
- orchestration — (uncountable) the arrangement of music for performance by an orchestra.
- orchidologist — someone who is knowledgeable in orchidology
- orchiectomies — Plural form of orchiectomy.
- organ whistle — a steam or air whistle in which the jet is forced up against the thin edge of a pipe closed at the top.