18-letter words containing a, s, t, o, r
- work-study program — a program enabling high-school or college students to combine academic work with actual job experience.
- 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.
- x-ray spectrometer — a spectrometer using x-rays to activate the inner electrons of an atom in order to separate and identify the chemical constituents of a substance and their concentrations.
- x-ray spectrometry — the use of an x-ray spectrometer.
- yerkes observatory — an astronomical observatory located in Williams Bay, Wisconsin, affiliated with the University of Chicago, and having a 40-inch (102-cm) refracting telescope, the largest refractor in the world.
- young conservative — a member of the youth section of the United Kingdom Conservative Party
- zone of saturation — the ground below the water table