co-star
UK[ˈkəʊ stɑː(r)]US[ˈkoʊ stɑːr]
v
to perform as a star together with another actor or actress in a film, play, etc.
n
an actor or actress who performs as a star together with another in a film, play, etc.
Morpheme Breakdown
co
star
co
together
star
leading performer
Etymology
The word 'co-star' is a modern compound formed within the English language. The prefix 'co-', derived from the Latin preposition cum (with), was borrowed into English to indicate association or partnership. The noun 'star' has Germanic origins, tracing back to Proto-Indo-European h₂stḗr, but its meaning shifted metaphorically from a celestial body to a celebrated theatrical performer. The compound logically combines these elements: 'co-' (together) + 'star' (leading performer) to explicitly denote a shared leading role, reflecting the collaborative nature of film and theater where top billing can be shared.
Analysis
Structure: co (together) + star (leading performer)
co: from Latin com- meaning "together, with". In this word, it functions as a prefix indicating joint action or partnership.
star: from Old English steorra, meaning "celestial body". Its modern theatrical sense, meaning a leading performer, emerged in the 18th century. In this compound, it functions as the root noun denoting the primary actor.
Examples
She will co-star with the award-winning actor in the new historical drama.
The film's success was due in part to the chemistry between its two co-stars.
He was thrilled to be offered a role co-starring in a major studio production.