regulus

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The metallic mass that sinks to the bottom of a furnace or crucible during smelting.
2. n. A relatively impure intermediate product of various ores in smelting.

Century Dictionary and Cyclopedia

1. n. In ornithology: An old name of the goldcrest or crested wren of Europe; a kinglet.
2. n. The typical genus of Regulinæ; the kinglets. The common goldcrest of Europe is R. cristatus (see cut under goldcrest); the fire-crested wren of the same country is R. ignicapillus. The corresponding species of America is the golden-crowned kinglet, R. satrapa. The ruby-crowned kinglet is R. calendula. See kinglet.
3. n. In alchemy and early chemistry, the reduced or metallic mass obtained in the treatment of various ores, particularly those of the semi-metals (see metal); especially, metallic antimony (regulus antimonii): but various alloys of antimony, other brittle metals, and even the more perfect metals were also occasionally so called, to indicate that they were in the metallic condition.
4. n. A very white star, of magnitude 1.4, on the heart of the Lion; a Leonis.
5. n. In geometry, a ruled surface or singly infinite system of straight lines, where consecutive lines do not intersect.
6. n. In metallurgy: The metallic mass which sinks to the bottom of a furnace or crucible, separating itself from the slag by gravity.
7. n. An intermediate product obtained in smelting ores, especially those of copper, lead, silver, and nickel, and consisting chiefly of metallic sulphids.
8. n. One set of generators of a quadric surface; the system of straights that meet three non-incident straights.
9. n. A configuration of lines which satisfy three conditions, and therefore depend on only one parameter.

Wiktionary

1. n. an impure metal formed beneath slag during the smelting of ores.

GNU Webster's 1913

1. n. A petty king; a ruler of little power or consequence.
2. n. The button, globule, or mass of metal, in a more or less impure state, which forms in the bottom of the crucible in smelting and reduction of ores.
3. n. A star of the first magnitude in the constellation Leo; -- called also the Lion's Heart.

WordNet 3.0

1. n. a genus of birds of the family Sylviidae including kinglets
2. n. the brightest star in Leo