underflow

(noun, verb)

noun

1. (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

2. (computing) The error condition that results from an attempt to retrieve an item from an empty stack

verb

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.