18-letter words containing r, a, i, n, s, t
- warrant of fitness — a six-monthly certificate required for motor vehicles certifying mechanical soundness
- water stick insect — a slender sticklike flightless water bug, Ranatra linearis, that is predatory on small creatures such as water fleas
- watson-crick model — a widely accepted model for the three-dimensional structure of DNA, featuring a double-helix configuration for the molecule's two hydrogen-bonded complementary polynucleotide strands.
- weberian apparatus — (in certain fishes) a chain of small bones and ligaments connecting the inner ear with the air bladder.
- western alienation — a feeling of resentment by some inhabitants of western Canada against perceived favouritism by the national government towards the eastern provinces
- westinghouse brake — a railroad air brake operated by compressed air.
- white man's burden — the alleged duty of white colonizers to care for nonwhite indigenous subjects in their colonial possessions.
- wildlife sanctuary — an area where wild animals and plants are protected
- winged everlasting — a bushy composite plant, Ammobium alatum, of Australia, having winged branches, javelin-shaped leaves, and white flowers.
- women at point sur — a narrative poem (1927) by Robinson Jeffers.
- women's liberation — a movement to combat sexual discrimination and to gain full legal, economic, vocational, educational, and social rights and opportunities for women, equal to those of men.
- wrangell mountains — a mountain range in SE Alaska, extending into the Yukon, Canada. Highest peak: Mount Blackburn, 5037 m (16 523 ft)
- writ of assistance — a writ issued by a superior colonial court authorizing officers of the British crown to summon aid and enter and search any premises.
- young conservative — a member of the youth section of the United Kingdom Conservative Party
- yves saint laurent — Louis Stephen [lwee ste-fen] /lwi stɛˈfɛn/ (Show IPA), 1882–1973, prime minister of Canada 1948–57.
- zone of saturation — the ground below the water table