One who experiments; a person who conducts experiments or performs experimental work.
From experiment + -ator (agent noun suffix meaning 'one who does'). The -ator suffix, from Latin, creates nouns describing someone who performs the action of the root verb. This is a formal or archaic term for experimenter.
You'll rarely hear this word today because 'experimenter' is shorter and more common, but 'experimentator' sounds like something a mad scientist character would call themselves in a Victorian steampunk novel!
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