Experiment
Middle English: from Old French, or from Latin experimentum, from experiri ‘try’. Compare with experience and expert.
wiktionary
From Middle English experiment, from Old French esperiment (French expérience), from Latin experimentum(“experience, attempt, experiment”), from experior(“to experience, to attempt”), itself from ex + *perior, in turn from Proto-Indo-European *per-.
etymonline
experiment (n.)
mid-14c., "action of observing or testing; an observation, test, or trial;" also "piece of evidence or empirical proof; feat of magic or sorcery," from Old French esperment "practical knowledge, cunning; enchantment, magic spell; trial, proof, example; lesson, sign, indication," from Latin experimentum "a trial, test, proof, experiment," noun of action from experiri "to try, test," from ex "out of" (see ex-) + peritus "experienced, tested," from PIE *per-yo-, suffixed form of root *per- (3) "to try, risk."
experiment (v.)
"make trial, operate (on something) so as to discover some unknown fact or to establish it when known," late 15c., from experiment (n.). Intransitive sense by 1787. Related: Experimented; experimenting.
