18-letter words containing o, n, t, l
- aristotles-lantern — a complex arrangement of muscles and calcareous teeth and plates forming an eversible organ in most echinoids, functioning in mastication.
- artificial horizon — an aircraft instrument, using a gyroscope, that indicates the aircraft's attitude in relation to the horizontal
- asbestos longjohns — (humour) Notional garments donned by Usenet posters just before emitting a remark they expect will elicit flamage. This is the most common of the asbestos coinages. Also "asbestos underwear", "asbestos overcoat", etc.
- assignment problem — (mathematics, algorithm) (Or "linear assignment") Any problem involving minimising the sum of C(a, b) over a set P of pairs (a, b) where a is an element of some set A and b is an element of set B, and C is some function, under constraints such as "each element of A must appear exactly once in P" or similarly for B, or both. For example, the a's could be workers and the b's projects. The problem is "linear" because the "cost function" C() depends only on the particular pairing (a, b) and is independent of all other pairings.
- astronomical clock — a complex clock showing astronomical phenomena, such as the phases of the moon
- at someone's elbow — very close to someone; easy to reach
- australian doubles — an unusual formation in doubles in which the server's partner is positioned on the same side of the court as the server.
- australopithecines — Plural form of australopithecine.
- auxiliary equation — characteristic equation (def 1b).
- auxiliary-equation — Mathematics. the characteristic polynomial of a given matrix, equated to zero. Also called auxiliary equation. an equation with one variable and equated to zero, which is derived from a given linear differential equation and in which the coefficient and power of the variable in each term correspond to the coefficient and order of a derivative in the original equation.
- axile placentation — a type of placenta structure in an ovary with the ovules forming at the angles where the septa join the central placenta
- axis of revolution — an axis in a plane, about which an area is revolved to form a solid of revolution.
- ayatollah khomeini — Ayatollah Ruhollah [roo-hoh-luh;; Persian roo-haw-lah] /ruˈhoʊ lə;; Persian ˌru hɔˈlɑ/ (Show IPA), 1900?–89, Islamic leader of Iran 1979–89.
- bachelor apartment — a flat consisting of one room that is used as a sitting room and bedroom, as well as a kitchenette and a bathroom
- bachelor's-buttons — any of various plants of the daisy family with button-like flower heads
- balance an account — If you balance an account, you adjust entries in the account in order to make the credit and debit totals equal.
- balanced computing — (jargon) Matching computer tools to job activities so that the computer system structure parallels the organisation structure and work functions. Both personal computers and employees operate in a decentralised environment with monitoring of achievement of management objectives from centralised corporate systems.
- ball-and-claw foot — a foot having the form of a bird's claw grasping a ball.
- band-tailed pigeon — a wild pigeon, Columba fasciata, of western North America, having a gray band on its tail.
- bartholin's glands — two small reddish-yellow glands, one on each side of the vaginal orifice, that secrete a mucous lubricating substance during sexual stimulation in females
- basal conglomerate — a conglomerate deposited on an erosion surface and constituting the bottom layer of a stratigraphic series.
- battery eliminator — eliminator (def 2).
- battery-eliminator — a person or thing that eliminates.
- battle of clontarf — a battle fought in 1014, near Dublin, in the Republic of Ireland, in which the Danes were defeated by the Irish but the Irish king, Brian Boru, was killed
- battle of omdurman — a battle (1898) in which the Mahdi's successor and his Ansar followers were defeated by Lord Kitchener's British forces
- battleground-state — a state of the U.S. in which the Democratic and Republican candidates both have a good chance of winning and that is considered key to the outcome of a presidential election: the swing states of Ohio and Indiana.
- be lost in thought — If you are lost in thought, you give all your attention to what you are thinking about and do not notice what is going on around you.
- be lost on someone — If advice or a comment is lost on someone, they do not understand it or they pay no attention to it.
- bedlington terrier — a lithe, graceful breed of terrier having a long tapering head with no stop and a thick fleecy coat
- bel and the dragon — a book of the Apocrypha that is included as chapter 14 of Daniel in the Douay Bible.
- benzyl thiocyanate — a colorless, crystalline, water-insoluble solid, C 8 H 7 NS, used as an insecticide.
- bernoulli equation — Hydrodynamics. Bernoulli's theorem (def 2).
- bill of indictment — a formal document accusing a person or persons of crime, formerly presented to a grand jury for certification as a true bill but now signed by a court official
- bill of quantities — a document drawn up by a quantity surveyor providing details of the prices, dimensions, etc, of the materials required to build a large structure, such as a factory
- biological control — the control of destructive organisms by the use of other organisms, such as the natural predators of the pests
- biological parents — the biological mother and father of a child
- bipolar transistor — (electronics) A transistor made from a sandwich of n- and p-type semiconductor material: either npn or pnp. The middle section is known as the "base" and the other two as the "collector" and "emitter". When used as an amplifying element, the base to emitter junction is in a "forward-biased" (conducting) condition, and the base to collector junction is "reverse-biased" or non-conducting. Small changes in the base to emitter current (the input signal) cause either holes (for pnp devices) or free electrons (for npn) to enter the base from the emitter. The attracting voltage of the collector causes the majority of these charges to cross into and be collected by the collector, resulting in amplification. Contrast field effect transistor.
- birth control pill — an oral contraceptive for women, containing the hormones estrogen and progesterone or progesterone alone, that inhibits ovulation, fertilization, or implantation of a fertilized ovum, causing temporary infertility.
- birth-control pill — an oral contraceptive for women, containing the hormones estrogen and progesterone or progesterone alone, that inhibits ovulation, fertilization, or implantation of a fertilized ovum, causing temporary infertility.
- bitwise complement — The bitwise complement of a bit field is a bit field of the same length but with each zero changed to a one and vice versa. This is the same as the ones complement of a binary integer.
- black-necked stork — a large Australian stork, Xenorhyncus asiaticus, having a white plumage, dark green back and tail, and red legs
- blanche of castile — ?1188–1252, queen consort (1223–26) of Louis VIII of France, born in Spain. The mother of Louis IX, she acted as regent during his minority (1226–36) and his absence on a crusade (1248–52)
- blocking capacitor — a capacitor that blocks the passage of direct current but allows alternating current to pass
- board of elections — a bipartisan board appointed usually by local authorities and charged with control of elections and voting procedure.
- boltzmann constant — the ratio of the gas constant to the Avogadro constant, equal to 1.380 650 × 10–23 joule per kelvin
- bomb disposal unit — a unit of the police or armed services specializing in bomb disposal
- boole's inequality — the theorem that the probability of several events occurring is less than or equal to the sum of the probabilities of each event occurring.
- born to the purple — being of royal or high birth
- bottle-nosed whale — any of various beaked whales of the family Hyperoodontidae, characterized by a bulbous forehead, especially Hyperoodon ampullatus of the North Atlantic.
- bottlenose dolphin — any dolphin of the genus Tursiops, esp T. truncatus, some of which have been kept in captivity and trained to perform tricks