The generalization of the concept of "life" beyond earth-style carbon-based biochemistry is still in active debate. As far as I'm aware, the most consensual definition is the one called "lyfe" (to distinguish from the aforementioned carbon-based chemistry, a concept formulated by Stuart John Bartlett and John L Wong in 2020). It has four characteristics:
- dissipation : the ability to use/convert energy sources (arguably a thing that stars do)
- autocatalysis : the ability to grow exponentually (I guess you could argue it happens during the initial star formation before it reaches an equilibrium... Maybe)
- homeostasis : the ability to compensate for small disturbances in environment (unclear to me what those disturbances and what this adaptation would be in the case of stars)
- learning : the ability to record, process and adapt to information (no such thing in stars as far as I know)