According to Oxford, the definition of science is:
“the intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment.” I am not saying that this definition is incorrect but I have a better and simpler meaning of the word “Science”!
In Sanskrit, there is a word called “विज्ञान” (Vigyān). “gyān” means “knowledge” and “विज्ञान” (Vigyan) which is a short form of “विशेष ज्ञान” (Vishesh gyān) which literally means “Special Knowledge”. So, in other words, science is nothing but the “Special Knowledge”, it can be about the physical object or mental emotion, tangible or intangible, bodily or ethereal!