An infinitely small quantity which is assumed to admit of no further division.
That which cannot be divided or split.
Incapable of being divided; atomic.
Incapable of being divided by a specific integer without leaving a remainder.
A non-zero quantity whose magnitude is smaller than any positive number (by definition it is not a real number).
Incalculably, exceedingly, or immeasurably minute; vanishingly small.
Very small.
Of or pertaining to values that approach zero as a limit.