[reg-yuh-luh s]

noun, plural reg·u·lus·es, reg·u·li [reg-yuh-lahy] /ˈrɛg yəˌlaɪ/.

(initial capital letter) Astronomy. a first magnitude star in the constellation Leo.
  1. the metallic mass that forms beneath the slag at the bottom of the crucible or furnace in smelting ores.
  2. an impure intermediate product obtained in smelting ores.

Origin of regulus

1550–60; < Latin rēgulus literally, little king (diminutive of rēx); in early chemistry, antimony, so called because it readily combines with gold (the king of metals); see -ule


[reg-yuh-luh s]


Marcus A·til·i·us [uh-til-ee-uh s] /əˈtɪl i əs/, died 250? b.c., Roman general. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for regulus

Historical Examples of regulus

  • Latitude of camp 26 degrees 42 minutes 43 seconds by Regulus.

  • Our intention, it must be confessed, however, was to seize the Regulus in the confusion.

    Ned Myers

    James Fenimore Cooper

  • The same decision was made, as to the whole eight of us, that had come on in the Regulus.

    Ned Myers

    James Fenimore Cooper

  • He was saved and carried on board the 'Regulus' by the intrepidity of young Dill.


    Charles James Lever

  • Mr. Regulus thought with Dr. Harlowe, that it was a pity I was not at school.

    Ernest Linwood

    Caroline Lee Hentz

British Dictionary definitions for regulus


noun plural -luses or -li (-ˌlaɪ)

impure metal forming beneath the slag during the smelting of ores
Derived Formsreguline, adjective

Word Origin for regulus

C16: from Latin: a petty king, from rēx king; formerly used for antimony, because it combines readily with gold, thought of as the king of metals




Marcus Atilius (ˈmɑːkəs əˈtɪlɪəs). died ?250 bc, Roman general; consul (267; 256). Captured by the Carthaginians in the First Punic War, he was sent to Rome on parole to deliver the enemy's peace terms, advised the Senate to refuse them, and was tortured to death on his return to Carthage




the brightest star in the constellation Leo. Visual magnitude: 1.3; spectral type: B8; distance: 69 light years
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for regulus



bright star in constellation Leo, 1550s, Modern Latin, apparently first so-called by Copernicus, literally "little king," diminutive of rex "king;" probably a translation of Basiliskos "little king," a Hellenistic Greek name for the star, mentioned in Geminos and Ptolemy (in the "Almagest," though elsewhere in his writings it is usually "the star on the heart of Leo"); perhaps a translation of Lugal "king," said to have been the star's Babylonian name. Klein holds it to be a corruption of Arabic rijl (al-asad) "paw of the lion" (cf. Rigel).

Online Etymology Dictionary, © 2010 Douglas Harper

regulus in Science



A bright triple star in the constellation Leo, with an apparent magnitude of 1.35. Scientific name: Alpha Leonis.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.