18-letter words containing p, i, e, r, o
- vermiform appendix — a narrow, blind tube protruding from the cecum, having no known useful function, in humans being 3 to 4 inches (8 to 10 cm) long and situated in the lower right-hand part of the abdomen.
- videotape recorder — a device for recording television programs on magnetic tape for delayed transmission or for storage.
- vigoureux printing — a printing method in which worsted fibers are printed with the desired color while in sliver form and then processed into yarn, producing a mixed color in the spun yarn and woven fabric.
- 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.
- warehouse capacity — the amount of storage space in a warehouse
- western isles pony — a breed of large pony, typically grey, with a dense waterproof coat. The only surviving variety is the Eriskay pony
- white iron pyrites — marcasite
- wild passionflower — the maypop, Passiflora incarnata.
- wildlife programme — (esp on television) a documentary whose subject is wild animals in their natural habitat or undomesticated fauna and flora generally
- wilson's phalarope — a phalarope, Phalaropus tricolor, that breeds in the prairie regions of North America and winters in Argentina and Chile.
- wireless telephone — Now Rare. radiotelephony.
- wireless telephony — Now Rare. radiotelephony.
- women at point sur — a narrative poem (1927) by Robinson Jeffers.
- working hypothesis — See under hypothesis (def 1).