18-letter words containing p, h, l, y, c, t
- spectroheliography — the process of obtaining an image of the sun in light of a particular wavelength, such as calcium or hydrogen, showing the distribution of the element over the surface and in the solar atmosphere, using a spectroheliograph
- spherical geometry — the branch of geometry that deals with figures on spherical surfaces.
- spotted flycatcher — a European woodland songbird, Muscicapa striata, with a greyish-brown streaked plumage: family Muscicapidae (Old World flycatchers)
- the encyclopedists — the writers of the French Encyclopedia (1751-72) edited by Diderot and d'Alembert, which contained the advanced ideas of the period
- the family compact — the ruling oligarchy in Upper Canada in the early 19th century
- the-cocktail-party — a play in verse (1950) by T. S. Eliot.
- to hold your peace — If you hold or keep your peace, you do not speak, even though there is something you want or ought to say.