a person who is an expert in or who studies one of the natural or physical sciences, or who puts scientific methods into practice
The earliest known use of this word occurs in a report (1834) of a meeting of the British Association for the Advancement of Science, where it was proposed – but rejected – that it should be adopted as a general name for a student of natural science. It was introduced, apparently independently, by William Whewell in 1840. The word did not win widespread acceptance for many years; as late as 1890 it was criticized as ‘an ignoble Americanism’. The form sciencist was recorded earlier, in 1785, but in the sense ‘a person employing scientific principles’. Earlier terms for a person practising science include philosopher, natural philosopher, and naturalist, but none of these is precisely equivalent to the modern term