18-letter words containing e, r, i, t, a, n
- thermal efficiency — the ratio of the work output of a heat engine to the heat input expressed in the same units of energy.
- thioarsenious acid — any of a group of hypothetical acids, H3AsS3, HAsS2, and H4As2S5, known only in the forms of their salts
- third man argument — (in the philosophy of Aristotle) the argument against the existence of Platonic Forms that since the Form of Man is itself a perfect man, a further form (the "third" man) would be required to explain this, and so ad infinitum
- thorfinn karlsefni — 980–after 1007, Icelandic navigator, explorer, and leader of early colonizing expedition to Vinland, in North America.
- threatened species — a species likely, in the near future, to become an endangered species within all or much of its range.
- three-day eventing — participation in a three day equestrian competition consisting of dressage, cross-country jumping, and stadium jumping
- timber rattlesnake — a rattlesnake, Crotalus horridus horridus, of the eastern U.S., usually having the body marked with dark crossbands.
- to bear witness to — If a person or thing bears witness to something, they show or say that it exists or happened.
- to cast aspersions — If you cast aspersions on someone or something, you suggest that they are not very good in some way.
- to scrape a living — If you say that someone scrapes a living or scratches a living, you mean that they manage to earn enough to live on, but it is very difficult. In American English, you say they scrape out a living or scratch out a living.
- to speak your mind — If you speak your mind, you say firmly and honestly what you think about a situation, even if this may offend or upset people.
- traditional weapon — a weapon having ceremonial tribal significance, such as an assegai or knobkerrie
- traffic controller — a person whose job is to control the flow of air traffic
- tranquillizer dart — a dart filled with a tranquillizer that is shot from a gun in order to temporarily sedate an animal so that it may be handled safely
- transfinite number — an infinite cardinal or ordinal number.
- transient response — A transient response of a circuit is a temporary change in the way that it behaves due to an external excitation, that will disappear with time.
- transit instrument — Astronomy. meridian circle.
- transit theodolite — a theodolite having a telescope that can be transited.
- transition element — any element in any of the series of elements with atomic numbers 21–29, 39–47, 57–79, and 89–107, that in a given inner orbital has less than a full quota of electrons.
- translation agency — an organization that provide people to translate speech or writing into a different language
- transmission brake — A transmission brake is a brake that operates on the transmission system of a vehicle rather than directly on the wheels.
- transporter bridge — a bridge for carrying passengers and vehicles by means of a platform suspended from a trolley.
- transrectification — rectification occurring in one circuit as a result of the application of an alternating voltage to another circuit.
- transverse section — cross section (def 1).
- traveling salesman — a male representative of a business firm who travels in an assigned territory soliciting orders for a company's products or services.
- travelling library — a mobile library in which a vehicle such as a van delivers books to be borrowed
- treaty obligations — obligations or duties that must be carried out by a party as according to a treaty they have entered into
- treaty of waitangi — a treaty signed in 1840 by Māori chiefs and a representative of the British Government, providing the basis for the British annexation of New Zealand
- triangle of forces — a triangle whose sides represent the magnitudes and directions of three forces whose resultant is zero and which are therefore in equilibrium
- triarylmethane dye — any of the class of dyes containing three aryl groups attached to a central carbon atom: used chiefly for dyeing cotton, wool, and silk.
- trickle irrigation — drip irrigation.
- tristan und isolde — a music drama (composed, 1857–59; première, 1865) by Richard Wagner.
- trobriand islander — a native or inhabitant of the Trobriand Islands of Papua New Guinea
- turbine ventilator — a ventilator, usually mounted on the roof of a building, deck of a ship, etc., having at its head a globular, vaned rotor that is rotated by the wind, conveying air through a duct to and from a chamber below.
- two-minute warning — a time-out called by an official to notify both teams that two minutes remain in a half.
- two-tier financing — a form of lending in which the debt is divided into two separate parts, as in a first and second mortgage held by an individual on a single property
- ultrasonic testing — the scanning of material with an ultrasonic beam, during which reflections from faults in the material can be detected: a powerful nondestructive test method
- ultrasonic welding — the use of high-energy vibration of ultrasonic frequency to produce a weld between two components which are held in close contact
- under the aegis of — guided or protected by
- under-compensation — to compensate or pay less than is fair, customary, or expected.
- under-depreciation — decrease in value due to wear and tear, decay, decline in price, etc.
- under-registration — the act of registering.
- unearned increment — the increase in the value of property, especially land, due to natural causes, as growth of population, rather than to any labor or expenditure by the owner.
- unfair competition — acts done by a seller to confuse or deceive the public with intent to acquire a larger portion of the market, as by cutting prices below cost, misleading advertising, selling a spurious product under a false identity, etc.
- unilateral neglect — a symptom of brain damage in which a person is unaware of one side of his or her body and of anything in the external world on the same side
- united arab states — a former (1958–61) federation of the United Arab Republic (Egypt and Syria) and Yemen.
- united states army — the permanent or regular military land force of the United States, under the authority of the Department of Defense since 1947. Abbreviation: USA.
- universal negative — a proposition of the form “No S is P.” Symbol: E, e.
- universalizability — the thesis that any moral judgment must be equally applicable to every relevantly identical situation
- university faculty — a division within a university comprising one subject area, or a number of related subject areas