18-letter words containing h, e, l, n
- oath of allegiance — pledge to one's nation
- octachlorobiphenyl — (organic compound) Either of twelve isomers of the polychlorinated biphenyl containing eight chlorine atoms.
- oil of catechumens — holy oil used in baptism, the ordination of a cleric, the coronation of a sovereign, or in the consecration of a church.
- old man of the sea — (in The Arabian Nights' Entertainments) an old man who clung to the shoulders of Sindbad the Sailor for many days and nights.
- on the danger list — critically ill in hospital
- one's heart bleeds — used to express sympathetic grief, but often used ironically
- optical brightener — an additive that dyes and brightens fabric or paper
- oriental cockroach — a dark-brown cockroach, Blatta orientalis, thought to have originated in Asia but now nearly cosmopolitan in distribution.
- oriental shorthair — any of a breed of domestic cat, similar to the Siamese but with greenish eyes and often a coat of a solid color
- over the long term — in the future
- overnight telegram — a type of domestic telegram sent at a reduced rate with a minimum charge for 10 words or less and accepted until midnight for delivery the following day.
- palaeoanthropology — the branch of anthropology concerned with primitive man
- palm beach gardens — a city in SE Florida, near North Palm Beach.
- paraurethral gland — any of a group of vestigial glands located in the posterior wall of the urethra in women.
- pennsylvania dutch — the descendants of 17th- and 18th-century settlers in Pennsylvania from southwest Germany and Switzerland.
- peter and the wolf — a composition by Sergei Prokofiev written in 1936. It is a children's story with both music and text, spoken by a narrator accompanied by the orchestra
- phanerocrystalline — (of a rock) having the principal constituents in the form of crystals visible to the naked eye.
- phenol coefficient — the number indicating the effectiveness of a disinfectant as a germicide relative to phenol, which is arbitrarily assigned the number 1: based on the time required to kill a given quantity of a specific type of bacteria.
- phenylacetaldehyde — a colorless, oily, water-insoluble liquid, C 3 H 1 4 O, having a hyacinthlike odor: used chiefly in perfumery.
- phosphatidylserine — any of a class of phospholipids occurring in biological membranes and fats
- phthalic anhydride — a white, crystalline, slightly water-soluble solid, C 8 H 4 O 3 , used chiefly in the manufacture of dyes, alkyd resins, and plasticizers.
- physical education — systematic instruction in sports, exercises, and hygiene given as part of a school or college program.
- physical inventory — To carry out a physical inventory is to count all the stock on hand.
- phytohemagglutinin — a lectin, obtained from the red kidney bean, that binds to the membranes of T cells and stimulates metabolic activity, cell division, etc.
- pine tree shilling — a silver coin minted in Massachusetts in the mid to late 17th century, named for the pine tree within a circle shown on the obverse side.
- plains grasshopper — a large, destructive short-horned grasshopper, Brachystola magna, of the western U.S., marked by pinkish hind wings.
- planned parenthood — an organization that gives out information on the planning of the number and spacing of the births of one's children, as through the use of birth-control measures
- plight one's troth — to make a promise of marriage
- plumber's merchant — a shop or business that sells things needed for the job of installing and repairing pipes, fixtures, etc, for water, drainage, and gas
- policeman's helmet — a Himalayan balsaminaceous plant, Impatiens glandulifera, with large purplish-pink flowers, introduced into Britain
- pollen mother cell — one of the mother cells that produce four microspores by meiosis.
- polyvinyl chloride — a white, water-insoluble, thermoplastic resin, derived by the polymerization of vinyl chloride: used chiefly for thin coatings, insulation, and pipings.
- prerelease showing — a showing of a film before it goes on general release
- process scheduling — multitasking
- psychogalvanometer — a type of galvanometer for detecting and measuring psychogalvanic currents.
- psychotechnologist — a specialist in psychotechnology
- pull one's head in — the upper part of the body in humans, joined to the trunk by the neck, containing the brain, eyes, ears, nose, and mouth.
- pull one's punches — to restrain the force of one's criticisms or actions
- pulp canal therapy — endodontics.
- random walk theory — the theory that the future movement of share prices does not reflect past movements and therefore will not follow a discernible pattern
- rare-earth element — any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons.
- regular hexahedron — a solid cube with six square faces
- reinvent the wheel — (jargon) To design or implement a tool equivalent to an existing one or part of one, with the implication that doing so is silly or a waste of time. This is often a valid criticism. On the other hand, automobiles don't use wooden rollers, and some kinds of wheel have to be reinvented many times before you get them right. On the third hand, people reinventing the wheel do tend to come up with the moral equivalent of a trapezoid with an offset axle.
- repayment schedule — a document detailing the specific terms of a borrower's loan, such as monthly payment, interest rate, due dates etc
- residential school — (in Canada) a boarding school maintained by the Canadian government for Indian and Inuit children from sparsely populated settlements
- return to the fold — come back home
- reverse angle shot — Movies. reverse shot.
- rhode island white — one of a dual-purpose American breed of chickens having white feathers and a rose comb.
- root canal therapy — endodontics.
- rotary clothesline — an apparatus of radiating spokes that support lines on which clothes are hung to dry