18-letter words containing t, o, r, s, i
- virginia snakeroot — any of various plants whose roots have been regarded as a remedy for snakebites, as the herb Aristolochia serpentaria (Virginia snakeroot) having a medicinal rhizome and rootlets, and the white-flowered Polygala senega (Seneca snakeroot) having a medicinal root.
- visiting professor — a professor from another institution invited to teach at a university or college for a limited period, usually for a semester or one academic year.
- visitor's passport — (formerly, in Britain) a passport, valid for one year and for certain countries only, that could be purchased from post offices
- voter registration — the requirement of citizens to become registered in order to vote
- 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
- 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.
- western alienation — a feeling of resentment by some inhabitants of western Canada against perceived favouritism by the national government towards the eastern provinces
- western isles pony — a breed of large pony, typically grey, with a dense waterproof coat. The only surviving variety is the Eriskay pony
- westinghouse brake — a railroad air brake operated by compressed air.
- white iron pyrites — marcasite
- wireless telephone — Now Rare. radiotelephony.
- wireless telephony — Now Rare. radiotelephony.
- with flying colors — with flying colors, with an overwhelming victory, triumph, or success: He passed the test with flying colors.
- 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.
- wood-burning stove — cooker: fueled by wood
- work out the kinks — If someone works out the kinks in a situation, they resolve the problems associated with it.
- working hypothesis — See under hypothesis (def 1).
- 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
- zone of saturation — the ground below the water table