Not ponderable; without sensible or appreciable weight; incapable of being weighed.
Difficult or impossible to comprehend or evaluate.
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.
Of inferior significance, size, or strength; ineffective, small, weak.
(Frequently) ill; poorly, sickly.