pref. Extremely. Used to modify adjectives describing a level or quality of difficulty; the connotation is often 'more so than it should be' (NP-complete problems all seem to be very hard, but so far no one has found a good a priori reason that they should be.)
"Getting this algorithm to perform correctly in every case is NP-annoying."
This is generalized from the computer-science terms 'NP-hard' and 'NP-complete'. NP is the set of Nondeterministic-Polynomial algorithms, those that can be completed by a nondeterministic Turing machine in an amount of time that is a polynomial function of the size of the input; a solution for one NP-complete problem would solve all the others.