An idealist.
Someone who supports or creates abstract art.
Related or tending to abstractionism, particularly art.
An imponderable question.
A factor that cannot be anticipated.
An imponderable substance or body; specifically, in the plural, a name formerly applied to heat, light, electricity, and magnetism.
Not ponderable; without sensible or appreciable weight; incapable of being weighed.
Difficult or impossible to comprehend or evaluate.