Regulus

UK: /ˈrɛɡjʊləs/ US: (reg′yə ləs)

Collins Concise English Dictionary © HarperCollins Publishers::

Regulus / ˈrɛɡjʊləs/ noun

1. 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

Regulus / ˈrɛɡjʊləs/ noun

1. the brightest star in the constellation Leo. Visual magnitude: 1.3; spectral type: B8; distance: 69 light years

WordReference Random House Unabridged Dictionary of American English © 2025

reg•u•lus  (reg′yə ləs), n., pl. -lus•es, -li  (-lī′). 

1. (cap.) [Astron.] a first magnitude star in the constellation Leo.
2. Metallurgy
   • the metallic mass that forms beneath the slag at the bottom of the crucible or furnace in smelting ores.
   • an impure intermediate product obtained in smelting ores.

• 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
• 1550–60

Reg•u•lus  (reg′yə ləs), n. 

Marcus A•til•i•us  (ə til′ē əs), died 250?b.c.,Roman general.

Collins Concise English Dictionary © HarperCollins Publishers::

regulus / ˈrɛɡjʊləs/ noun ( -luses, -li / -ˌlaɪ/)

1. impure metal forming beneath the slag during the smelting of ores

Etymology: 16th Century: 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

ˈreguline adjective