Reg"u*lus (-l?s), n.; pl. E. Reguluses (-z), L. Reguli (-l). [L., a petty king, prince, dim. of rex, regis, a king: cf. F. r'egule. See Regal.]
A petty king; a ruler of little power or consequence.
2. Chem. & Metal.
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.
⇒ The name was introduced by the alchemists, and applied by them in the first instance to antimony. I signifies little king; and from the facility with which antimony alloyed with gold, these empirical philosophers had great hopes that this metal, antimony, would lead them to the discovery of the philosopher's stone.
A star of the first magnitude in the constellation Leo; -- called also the Lion's Heart.
© Webster 1913.