Science (from Latin scientia, meaning "knowledge"[1]) is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.[2][3] In an older and closely related meaning, "science" also refers to a body of knowledge itself, of the type that can be rationally explained and reliably applied. -wiki
"the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment." -
“a systematically organized body of knowledge on a particular subject.” - dictionary
"knowledge about or study of the natural world based on facts learned through experiments and observation" - dictionary
According to Webster's New Collegiate Dictionary, the definition of science is "knowledge attained through study or practice," or "knowledge covering general truths of the operation of general laws, esp. as obtained and tested through scientific method [and] concerned with the physical world."