Biology teaches that organisms that carry out self-sustaining processes are,
by definition, alive. Live organisms can grow, though some have finished
growing. They respond to external stimuli, though some responses are subtle. They
reproduce if circumstances permit, in a multitude of ways. Through time,
living things adapt to their environment. Also, they can die.
I think that there is possibly some universal definition of life. It probably has something to do that it has to be a species that procreates, has some form of 'breathing', or something like that. It probably will be hard to define it exactly, but I think experts can define it.
I do not believe there is a universal definition of life. I believe each person has a different experiences and I think any attempt to define that would lead to a narrow view. Life can mean different things for different people. I like to focus on my family and happiness. Others like to focus on their career or success.
If you asked a scientist, a clergyman and a medical doctor to explain their definition of life, I believe you would get 3 very different answers. Does life begin at conception? Is a germ "life"? Is bacteria "life"? Is someone in a coma alive? Is a person breathing on their own alive if they have no brain activity? If we travel to another planet, could we assume we knew what "life" was?
While the understanding of what life means should be universal, it is not. There are varying degrees of life that often involve sentience. Sentience should not directly be involved in the definition of life, Beyond sentience, what would define life? The ability to reproduce cells? That would include crystals to an extent, so that is out. The ability to reproduce organisms? Some chemical combinations produce organisms, so that is out. There is no universal definition due to the uncertainty of what defines life. it differs from person to person and philosophy, often for good reasons.