Something which lasts for a short period of time.
Usually dry, but filling with water for brief periods during and after precipitation.
Lasting for a short period of time.
Existing for only one day, as with some flowers, insects, and diseases.
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.