underflow

under- +‎ flow, modelled on overflow.

underflow (plural underflows)

1. A current flowing below the surface.
2. (computing) A condition in which the value of a computed quantity is smaller than the smallest non-zero value that can be physically stored; usually treated as an error condition
3. (computing) The error condition that results from an attempt to retrieve an item from an empty stack

• overflow

underflow (third-person singular simple present underflows, present participle underflowing, simple past and past participle underflowed)

1. (computing) To trigger the condition in which the value of a computed quantity is smaller than the smallest non-zero value that can be physically stored.

• wonderful, wondreful