What is the definition of life?

Answer 1

Well there are many definitions, but the one below is one of the good ones.

"Life: the period of existence or activity of something inanimate." This definition is taken from the Random House Webster's Dictionary.

In biological (study of living organisms) terms, something that is alive is capable of reproducing, growing, has its own metabolism, evolves through time and reacts to stimuli (chemical, has senses, etc.). This definition excluses things such as viruses however, which do not have their own metabolism and so have to hijack a cell which does in order to reproduce. Some biologists do broaden the definition of living organism to include viruses, however.