Constellation whose mane and shoulders are known as "the Sickle" (3)
I believe the answer is:
leo
(Other definitions for leo that I've seen before include "Zodiacal lion" , "Horoscope sign" , "Star sign of one born on August 1" , "one of several popes" , "Name taken by 13 popes, the last dying in 1903 aged 93" .)