'Experimenter' definitions:

Definition of 'experimenter'

From: WordNet
noun
A research worker who conducts experiments
noun
A person who enjoys testing innovative ideas; "she was an experimenter in new forms of poetry"

Definition of 'Experimenter'

From: GCIDE
  • Experimenter \Ex*per"i*men`ter\, n. One who makes experiments; one skilled in experiments. -- Faraday. [1913 Webster]