Rasalgethi
noun
Ras·al·ge·thi
variants or less commonly Ras Algethi
ˈräs-ˌal-jə-ˈtē,
-al-ˈge-thē
astronomy
: a group of stars of the third magnitude that is seen in the constellation Hercules
Hercules resembles the constellation Orion but only has two stars along the belt (rather than three) and is not as bright as Orion but still recognizable. In Hercules, there is an interesting double star known as Rasalgethi, located above his head. 
Chris Pagan, Tulsa World (Oklahoma), 5 June 2011
Chris Pagan, Tulsa World (Oklahoma), 5 June 2011called also Alpha Herculis
Note: What is visible in the night sky as the star Rasalgethi is actually a group of three stars bound together gravitationally; one red giant and a binary system of a yellow giant and a yellow dwarf star.
Word History
Etymology
borrowed from New Latin, borrowed from Arabic ra’s al-jāthī, literally, “head of the kneeling one”
First Known Use
1780, in the meaning defined above