What is "lion's heart"

Regulus \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['e]gule. See Regal.]

1. 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.

   Note: The name was introduced by the alchemists, and applied by them in the first instance to antimony. It 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.
   --Ure.

3. (Astron.) A star of the first magnitude in the constellation Leo; -- called also the Lion's Heart.

Lion's Heart is a 1972 Hong Kong film.

Lion’s Heart is a teen-based volunteer program headquartered in California. The organization has several chapters in other states, such as Colorado, Connecticut, Florida, Georgia, Massachusetts, New Jersey, New York, Texas, and Wisconsin. It was founded in 2004 as a non-profit, non-fundraising group designed to “to inspire teens to have a positive impact in their communities through leadership and participation in volunteering, providing needed resources for causes that ignite their passions.”(From their mission statement, main website.)

Lion’s Heart has enrolled approximately 5,600+ members as of 2016. The organization has grown steadily and offers teenagers the opportunity to perform community service without fundraising or other requirements. The organization enrolls teens who are in 6th through 12th grades.

Lion’s Heart has become noted in California due to their presence among volunteer groups.