Dome, n. [F. dôme, It. duomo, fr. L. domus a house, domus Dei or Domini, house of the Lord, house of God; akin to Gr. � house, � to build, and E. timber. See Timber.] 1. A building; a house; an edifice; — used chiefly in poetry.
Approach the dome, the social banquet share. Pope.
2. (Arch.) A cupola formed on a large scale.
☞ “The Italians apply the term il duomo to the principal church of a city, and the Germans call every cathedral church Dom; and it is supposed that the word in its present English sense has crept into use from the circumstance of such buildings being frequently surmounted by a cupola.” Am. Cyc.
3. Any erection resembling the dome or cupola of a building; as the upper part of a furnace, the vertical steam chamber on the top of a boiler, etc.
4. (Crystallog.) A prism formed by planes parallel to a lateral axis which meet above in a horizontal edge, like the roof of a house; also, one of the planes of such a form.
☞ If the plane is parallel to the longer diagonal (macrodiagonal) of the prism, it is called a macrodome; if parallel to the shorter (brachydiagonal), it is a brachydome; if parallel to the inclined diagonal in a monoclinic crystal, it is called a clinodome; if parallel to the orthodiagonal axis, an orthodome. Dana.