Bible Dictionaries
Imponderable

Webster's Dictionary

(1):

(a.) Not ponderable; without sensible or appreciable weight; incapable of being weighed.

(2):

(n.) An imponderable substance or body; specifically, in the plural, a name formerly applied to heat, light, electricity, and magnetism, regarded as subtile fluids destitute of weight but in modern science little used.

Bibliography Information
Webster, Noah. Entry for 'Imponderable'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​i/imponderable.html. 1828.