Experimental means based on trying something new to see what happens. An experimental treatment, an experimental design, purely experimental.
In science it names a branch — experimental physics, as against theoretical — and a method: experimental evidence, an experimental study. In medicine, an experimental treatment is one not yet approved, which is a warning as much as a description. In music and art, experimental means deliberately breaking the usual rules, and it is used both admiringly and as a polite way of saying unlistenable.
1adjectiveexperimentalBased on trying something new to see what happens.
“The patient agreed to try an experimental drug that had never been used on humans.”
2adjectivedeliberatelyDeliberately breaking usual artistic rules.
“The band's experimental album had no choruses and songs that lasted twenty minutes.”
experimental is a quality of testing.
Latin experimentum means a trial or test, from experiri, to try — the same verb behind expert and peril. An expert is somebody who has tried things, and peril is what trying them risks.
Proto-Indo-European
*per-
Latin
experimentum — experience, attempt, experiment
Old French
esperiment
Middle English
experiment
English
experiment
English, today
experimental
Built from
From experiment + al. experiment comes 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-.
Etymology from Wiktionary, CC BY-SA