To not succeed in a venture or activity. Various permutations of the phrase can be turned into almost any part of speech.
<Cyb> my bin2hex function is failing it
<mewse> you fail it
<Linguica> failure of it indeed
An interjection signifying a shoddy internet service provider.
Christ, I'm getting like 25% packet loss and sustained downloads of 1.2 KB/s. DSL EXTREME!