noun, noun or participle which takes 'suru', intransitive verb
starring; playing the lead role
Used for the leading role in films, plays, TV dramas, etc. Can be used as a noun or with する to mean 'to star'.
彼はその映画で主演した。
He starred in that movie.
主演女優は誰ですか。
Who is the lead actress?
Compound of 主 (main) and 演 (perform).