Scientist

Scientist (pronounced sahy-uhn-tist)

A person who studies or practises any of the sciences or who uses scientific methods, especially in the physical or natural sciences.

1833: Modeled after artist, the construct was the Latin stem scientia (knowledge) +‎ -ist.  Science was from the Middle English science & scyence, from the Old French science & escience, from the Latin scientia (knowledge), from sciens, the present participle stem of scire (to know).  The -ist suffix was from the Middle English -ist & -iste, from the Old French -iste and the Latin -ista, from the Ancient Greek -ιστής (-istḗs), from -ίζω (-ízō) (the -ize & -ise verbal suffix) and -τής (-tḗs) (the agent-noun suffix).  It was added to nouns to denote various senses of association such as (1) a person who studies or practices a particular discipline, (2), one who uses a device of some kind, (3) one who engages in a particular type of activity, (4) one who suffers from a specific condition or syndrome, (5) one who subscribes to a particular theological doctrine or religious denomination, (6) one who has a certain ideology or set of beliefs, (7) one who owns or manages something and (8), a person who holds very particular views (often applied to those thought most offensive).

Natural Philosopher versus Scientist

Founded in 1831 and modelled on the Gesellschaft Deutscher Naturforscher und Ärzte (Society of German Researchers and Physicians), the British Association for the Advancement of Science (BAAS) was formed as an organisation open to anyone interested in science, unlike the exclusive Royal Society of London for Improving Natural Knowledge (usually styled as "Royal Society").  In an indication of the breadth of its attraction, at the meeting of the BAAS on 24 June 1834, unexpectedly in attendance was the poet Samuel Taylor Coleridge (1772-1834); he’d not left his home in Highgate Hill for years and would die within weeks.  That a poet should attend a meeting about science was not at the time a surprise, the division between science and the arts coming later and Taylor had previously written about the scientific method.

Scientists study all sorts of things.  Research like this can attract an Ig Nobel prize.

For most of history, those we would now think of as scientists had been called natural philosophers.  Coleridge declared true philosophers were those who sat in their armchairs and contemplated the cosmos; they did not scratch around in digs or fiddle with electrical piles.  Cambridge don, the Reverend William Whewell, an English polymath, responded by suggesting, by analogy with artist, they should be called scientists and added those studying physics could be styled physicists, the French having already applied physicien (physician) to the surgeons and etymologists once dated the word “scientist” from that meeting but it was later discovered Whewell had coined the term in 1833 and it first appeared in print a year later in his anonymous review of Mary Somerville's (1780-1872) On the Connexion of the Physical Sciences published in the Quarterly Review.  It took a while to catch on but was in wide use in the US by the late nineteenth century and the rest of the English-speaking world a few years later although as late as 1900 there were publishers which had scientist on their “not-acceptable” list.

Google Ngram: Because of the way Google harvests it data, the numbers represented by the ngrams are not of necessity accurate but, over decades they probably are broadly indicative.  While the numbers do bounce around a bit, as expected, beginning in the mid-nineteenth century, there was a sharp upward trend in the use of the word "scientist" in publications in English.