noun
stage career; life on the stage
Refers to a person's career or life spent performing in theater, dance, or similar stage arts.
彼女は若い頃から舞台生活を送っている。
She has been living a stage life since she was young.
長い舞台生活の中で、多くの役を演じてきた。
Over a long stage career, he has played many roles.
芸能生活 is broader, covering entertainment careers in general (TV, film, music), while 舞台生活 specifically refers to stage performance.
Compound of 舞台 (stage) and 生活 (life, living). The meaning is transparent from its components.