qualia
noun·/ˈkwɑː.li.ə/
The felt texture of experience as it is lived from inside. The redness of red, the sting of salt, the ache of nostalgia. Sensation can be treated as data, but qualia insists on privacy: experience as irreducibly personal.
He could describe the wavelength, but not the qualia—the particular red that made the memory hurt.
Etymology
From Latin quale "of what kind," pluralized in modern philosophy to name qualities of consciousness that resist reduction to measurement. A small word for a stubborn remainder.
Related Words
consciousnessthe domain in which qualia appear
phenomenologythe study of experience as lived
noumenonthe “thing-in-itself”; often contrasted in discussions of knowability
pareidoliaa perception phenomenon where experience outruns stimulus