Cleo is an English unisex name which originated as a shortened form of names such as Cleopatra (an Ancient Greek female name meaning “glory of the father”) or Cleopas (a contracted form of Cleopatros, the masculine form of Cleopatra). It derives from the Ancient Greek element kleosκλέος(glory, fame).
Cleo could also have originated as a variant spelling of Clio which derives from the same source above; in Greek mythology, Clio is one of the nine Muses, the muse of history and heroic poetry.
Gloria is a female given name which comes from the Latin word glōria meaning “glory, renown, fame”, used in praise, exaltation, or great honor of someone or something by common consent. It’s background is of obscure/uncertain origin; it may be related to Old Latin *gnōria (knowledge, fame) via PIE root word *ǵneh₃- (to know).
Gloria is also used in a religious sense, the name of several Christian liturgical hymns in praise of God, so it also connotes a sense of “divine glory”.
Gloria is also a Spanish, Portuguese, and Italian surname which originated either a matronymic name or as an occupational name for a singer, in reference to the hymn Gloria in excelsis Deo (“Glory to God in the highest”).
Origin: uncertain, likely from a Proto-Indo-European source
Meaning: “glory, renown, praise, fame”
Usage: English, Latin, Italian, Spanish, German
Nicknames: Glory, Ria, Lori
Gloriana (an elaborated form of Gloria created by English poet EdmundSpenser in 1590 for his poem The Faerie Queen)