Refresh one’s knowledge, as in I must rub up on my French before we leave for Paris. [ Second half of 1700s ]
noun, plural rubies. 1. a red variety of corundum, used as a gem. 2. something made of this stone or one of its imitations, as a bearing in a watch. 3. a deep-red port wine. 4. deep red; carmine. 5. British Printing. a 5½-point type, nearly corresponding in size to American agate. adjective 6. ruby-colored: […]
- Ruby-crowned kinglet
[roo-bee-kround] /ˈru biˌkraʊnd/ noun 1. an olive-gray, American kinglet, Regulus calendula, the male of which has an erectile, ruby crest.
noun 1. glass having a red color resulting from the addition of gold, copper, or selenium to the batch. 2. any glass of a dark red color. noun 1. glass that has a deep rich red colour produced from oxides of various minerals, such as lead, copper, and iron
noun 1. a solid-state, pulsed laser that uses a ruby crystal to produce a very strong beam of red coherent light, used in making holographs and in cosmetic instruments.