|1.||All mouth and no trousers|
Someone who can talk a good game but cannot back himself up. Relies heavily on others who are his opposite (able, but a poor orator) to sort out any problems. One who makes idle threats.
Random13yearold: I'll hax your computer! I'll hack a virus!!!111
KFJ: You're all mouth and no trousers, but I'd love to see you "hack a virus".