There are perhaps a hundred different definitions of science on none of which there may be consensus. These definitions are not unlike the descriptions of the elephant by the six blind men: all of whom were partially right, but none totally so.
Recognizing this, let me offer my own definition and description of science, subject to the same constraint as any other.
“Science is a collective trans-national effort by Homo sapiens to understand, appreciate, and explain every aspect of perceived reality that has been acquired through thorough and systematic observation with the aid of instruments, concepts, and mathematical methods (when possible) in a coherent, consistent, sharable, verifiable, and rational framework, with the conviction that there are no supernatural entities behind natural phenomena.”
The totality of understanding and interpretation thus acquired constitutes the scientific knowledge of a given period. This knowledge is always in a dynamic state, susceptible to modification, improvement, and even total replacement as a result of further scientific activity.
There may be other modes of grasping other dimensions reality (presumed or actual), but the criteria for accepting their validity are different from the ones adopted by science: coherence, consistency, rationality, sharability, and trans-national verifiability.
V. V. Raman
Spurts of Thought 