18-letter words containing p, t, e, r, y
- white trumpet lily — a lily, Lilium longiflorum, of Japan, having fragrant, pure white, trumpet-shaped flowers nearly 7 inches (18 cm) in length.
- wireless telephony — Now Rare. radiotelephony.
- working hypothesis — See under hypothesis (def 1).
- 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.