Darwin did not use the word 'evolution' in any of his books or essays. He referred to his theory as 'modification with descent'. He used the phrase 'natural selection'. He may have used the phrase 'survival of the fittest' once or twice instead of 'evolution', though I am not sure.
Note: If you can find any verbatim quote from Darwin where he explicitly uses the word 'evolution', then please let us know !-)
'Evolution' was used before Darwin for more judicious reasons. The word has a sort of value judgement embedded in its meaning. Darwin purposely avoided value judgements when developing his theory. He was developing a general theory. He presented a lot of hypotheses when presenting his theory. However, the process that he describes is ethically neutral. 'Origin of the Species' has about as much moral purpose as 'Newtons Principia'.
Haekel was probably the person most responsible for the misuse of the word 'evolution'. Haeckel was an atheist but with mystical beliefs that he imposed on 'descent with modification'. He used the word evolution to denote 'modification with descent' maybe because there is a value judgement implicit in the word 'evolution'. Anyway, he had this theory that 'ontogeny recapitulates phylogeny' which he supported with great fervor.
Haekel used the word evolution to describe both 'modification with descent (i.e., phylogeny) with developmental change of the individual (i.e., ontogeny). In his view, there was a mystical force that guided both ontogeny and phylogeny.
Haekel was a great popularized of Darwin's theory. He was the one who combined Tildmann's recapitulation theory with Darwin's theory of 'modification with descent'. Darwin later accepted recapitulation theory but presented many qualifications. Darwin explicitly said that ontogeny
Haekel had a lot of racist and nationalist ideas that he folded into his theory. Sometimes, he presented his ideas in an exaggerated way that is sometimes referred to as fraud. However, he there may not have had conscious intent in doing so. In any case, he often tried to sweep facts under the rug when challenged.
Darwin accepted parts of his theory with reservations. Darwin claimed many times that recapitulation theory was only true sometimes. He specifically said that it could not apply when the juvenile state of the organism was under intense selection pressure. For instance, 'ontogeny recapitulates phylogeny' could not be true for insects in the larval stage because the larva are under different selection pressures than the adult. So Darwin could not be blamed for all the excesses perpetuated by Haekel.
I do not know exactly where Haekel got the word 'evolution', but he used it a lot. He could have gotten the word from scientists working on embryology, which started before Darwin. One scientist who preceded both Darwin and Haekel were Tildeman.
If it wasn't Haekel who coined the word evolution, it could be an earlier biologist. The German biologist, Tildmann, really did the pioneering work on embryos in development. He also wrote a monograph showing that Negroes could not be intellectually inferior to Caucasians. Lots of the experimental work on development really started with Tildeman. I suggest that he could have coined a German version of the word 'evolution'.
Other words that have been greatly misused have been falsely attributed to Darwin. The word 'mutation' is also attributed to Darwin very often. Darwin never used the word 'mutation'. He used the phrase 'spontaneous variation' for 'de nova mutations'. He used the phrase 'inherited variation' to include variations caused by recombination. He did not use the words 'gene' or 'allele'.
The word evolution is used in physics, although not in the same sense as biology. For instance, the mathematics of quantum mechanics has a concept referred to as an 'evolution operator'. Evolution operators are sometimes used in thermodynamics. On occasion, it is even used in classical mechanics. There is a model in quantum mechanics recently developed referred to as 'quantum Darwinism'. There is no value system inherent in the physicist's definition of the word 'evolution'.
If you can blame Darwin for using the word 'evolution', then surely you should blame Newton for using the word 'evolution'. Newton is not at fault for using the word 'evolution', although his theory has been described using the words. Darwin's Theory of 'modification with descent', like Newtonian mechanics, is a very general theory. Words used to describe both theories were added later as new discoveries were made. In fact, the word evolution has been used to describe orbital mechanics. I am sure that Newton never used the word evolution to describe the motion of a system of particles. However, mechanical systems evolve according to certain rules, too.