18-letter words containing a, s, t, r, w, i
- swarm intelligence — the collective behaviour of a group of animals, esp social insects such as ants, bees, and termites, that are each following very basic rules
- sweptwing aircraft — an aircraft which has wings that are swept (usually) backwards
- territorial waters — law: nation's boundaries
- the bird has flown — the person in question has fled or escaped
- the cat's whiskers — a person or thing that is excellent or superior
- to bear witness to — If a person or thing bears witness to something, they show or say that it exists or happened.
- treaty of rijswijk — a treaty signed at Rijswijk in the Netherlands in 1697, ending the War of the Grand Alliance
- ultrasonic welding — the use of high-energy vibration of ultrasonic frequency to produce a weld between two components which are held in close contact
- wandering minstrel — travelling performer
- wardrobe assistant — a person who assists the wardrobe mistress in a theatre
- warehouse capacity — the amount of storage space in a warehouse
- 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.
- whittaker chambers — Robert, 1802–71, Scottish publisher and editor.
- 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.
- withdrawal symptom — effects of stopping a drug
- 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.