in Roman religion, day of merriment and rejoicing in the Cybele-Attis cult and in the Isis-Osiris cult, March 25 and November 3, respectively. It was one of several days in the festival of Cybele that honoured Attis, her son and lover: March 15, his finding by Cybele among the reeds on the bank of the River Gallus; March 22, his self-mutilation; March 24, fasting and mourning at his death; and March 25, the Hilaria, rejoicing at his resurrection. Some of the activities on the Hilaria resembled those associated with April Fools' Day. November 3, the Hilaria of the Isis-Osiris cult, marked the resurrection of Osiris, husband of Isis.

in botany, genus of perennial grasses in the family Poaceae, consisting of about seven species native primarily to warm, dry areas of southern North America. They are known variously as galleta, big galleta, and curly mesquite.

Curly mesquite (H. belangeri) and galleta (H. jamesii) are palatable to livestock when fresh and green. All the species, however, are important range grasses.