2 Answers

sci·ence 
study of physical world: the study of the physical and natural world and phenomena, especially by using systematic observation and experiment
branch of science: a particular area of study or knowledge of the physical world
systematic body of knowledge: a systematically organized body of knowledge about a particular subject

1. a branch of knowledge or study dealing with a body of facts or truths systematically arranged and showing the operation of general laws: the mathematical sciences.

2. systematic knowledge of the physical or material world gained through observation and experimentation.

3. any of the branches of natural or physical science.

4. systematized knowledge in general.

5. knowledge, as of facts or principles; knowledge gained by systematic study.

Source >>>http://dictionary.reference.com/browse/science