Dictionary
im•pon•der•a•ble
Pronunciation: (im-pon'dur-u-bul), [key]—
adj.
not ponderable; that cannot be precisely determined, measured, or evaluated.
—
n.
an imponderable thing, force, agency, etc.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.