Get the details behind our redesign


[reg-yuh-luh s] /ˈrɛg yə ləs/
noun, plural reguluses, reguli
[reg-yuh-lahy] /ˈrɛg yəˌlaɪ/ (Show IPA)
(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.
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 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
British Dictionary definitions for reguli


noun (pl) -luses, -li (-ˌlaɪ)
impure metal forming beneath the slag during the smelting of ores
Derived Forms
reguline, adjective
Word Origin
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
Cite This Source
Word Origin and History for reguli
"bright star in constellation Leo," 1559, from L., lit. "little king," dim. of rex "king;" probably a translation of Basiliskos "little king," a Hellenistic Gk. 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," the Babylonian name for the star.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
reguli 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 © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of The Day

Difficulty index for regulus

Few English speakers likely know this word

Word Value for reguli

Scrabble Words With Friends