11-letter words containing r, i, o
- appreciator — to be grateful or thankful for: They appreciated his thoughtfulness.
- appressoria — a flattened and thickened tip of a hyphal branch, formed by some parasitic fungi, that facilitates penetration of the host plant.
- approaching — coming closer in time
- approbating — Present participle of approbate.
- approbation — Approbation is approval of something or agreement to it.
- approbative — showing approbation or approval
- appropinque — to approach
- appropriacy — the condition of delicate and precise fittingness of a word or expression to its context, even when it is chosen from a number of close synonyms
- appropriate — Something that is appropriate is suitable or acceptable for a particular situation.
- approvingly — to speak or think favorably of; pronounce or consider agreeable or good; judge favorably: to approve the policies of the administration.
- approximant — an articulation in which one articulator is close to another, but not sufficiently so to form a stop or a fricative.
- approximate — An approximate number, time, or position is close to the correct number, time, or position, but is not exact.
- apricot jam — a sweet preserve made from apricots
- aprioristic — belief in, or reliance upon, a priori reasoning, arguments, or principles.
- apron piece — (in a staircase) a header receiving the ends of rough strings, carriage pieces, and the joists of landings.
- aqua fortis — nitric acid
- aquaerobics — A form of aerobics done while in water.
- aquafortist — a person who makes engravings or etchings through the use of aqua fortis
- aquariology — The study of the fauna and flora of aquaria.
- arab legion — a police force (1920–56) under British supervision, responsible for keeping order among desert tribesmen in Trans-Jordan.
- arabidopsis — Any cress (or related plant) of the genus Arabidopsis.
- arabinoside — a glycoside yielding arabinose when hydrolysed
- arabization — transfer to Arab control
- arachidonic — related to arachidonic acid or the derivatives of arachidonic acid
- arachis oil — peanut oil.
- arachnoidal — relating to the arachnoid
- araeometric — relating to araeometry
- araliaceous — of, relating to, or belonging to the Araliaceae, a chiefly tropical family of trees, shrubs, or woody climbers having small clusters of whitish or greenish flowers. The family includes the ivy and ginseng
- arbitration — Arbitration is the judging of a dispute between people or groups by someone who is not involved.
- arbitrators — Plural form of arbitrator.
- arbor vitae — any of several Asian and North American evergreen coniferous trees of the genera Thuja and Thujopsis, esp Thuja occidentalis, having tiny scalelike leaves and egglike cones
- arborvitaes — Plural form of arborvitae.
- arboviruses — Plural form of arbovirus.
- archaeornis — an extinct primitive Jurassic bird, formerly placed in the genus Archaeornis but now thought to be a species of archaeopteryx
- archaeozoic — Archeozoic
- archbishops — Plural form of archbishop.
- archdiocese — An archdiocese is the area over which an archbishop has control.
- archegonial — relating to an archegonium
- archegonium — a female sex organ, occurring in mosses, spore-bearing vascular plants, and gymnosperms, that produces a single egg cell in its swollen base
- archeologic — (American spelling) alternative spelling of archaeologic.
- archicortex — (anatomy) Part of the allocortex, specifically three layered hippocampal cortexes necessary for hippocampus formation.
- archilochus — 7th century bc, Greek poet of Paros, notable for using his own experience as subject matter
- archipelago — An archipelago is a group of islands, especially small islands.
- architector — (obsolete) An architect.
- archtraitor — A chief or transcendent traitor.
- arctic zone — the section of the earth's surface lying between the Arctic Circle and the North Pole.
- arcticology — the scientific study of the Polar Regions.
- arctophilia — the practice of collecting teddy bears
- area office — a part of a business, organization, etc which is the most important office in a specific geographical area
- arenicolous — growing or living in sand or sandy places