Your search presumes there is one official definition of life, perhaps scribed upon stone tablets in nice differential equation notation. In reality, the word has given philosophers great trouble defining. Virtually all philosophers agree that a human is alive, as is a dog, as is a fish. Most philosophers generally agree that rocks are not alive. However, there is not a solid consensus regarding where the line should be drawn beyond those very easy examples.
Science itself has multiple definitions, but the most popular specifies a set of criteria for something to be alive:
- Homeostasis: regulation of the internal environment to maintain a constant state; for example, sweating to reduce temperature
- Organization: being structurally composed of one or more cells – the basic units of life
- Metabolism: transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
- Growth: maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.
- Adaptation: the ability to change over time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity, diet, and external factors.
- Response to stimuli: a response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion; for example, the leaves of a plant turning toward the sun (phototropism), and chemotaxis.
- Reproduction: the ability to produce new individual organisms, either asexually from a single parent organism or sexually from two parent organisms.
That would probably be the closes to an accepted definition of life that can be had from a scientific approach.
One can choose to go beyond that, and define one's own criteria for life. There's no rule against it, no thought police that will imprison you for your crimes. One could define life in a way which uses the language of quantum mechanics to do so. However, if you use an existing word like "life" and apply a new meaning to it, you can expect to have to defend your definition, for we typically like to keep the meanings of words as clutter-free as possible, and "life" is already quite cluttered.