Generica - the suburban squalour of America - fast food joints, strip malls, etc - that looks exactly the same, no matter where you are. Probaby coined by Douglas Coupland.

Garden leave - Paid cooling off period, typically three months, that your contract stipulates you cannot work before starting a new job. Used by city firms to prevent people walking straight into a new job with hot information.

Glasgow salad - Chips

Glocalisation - the natural end product of trying to 'think global and act local'. In practice often means window dressing your outlets to look like the real local businesses whose bankruptcy your chain's arrival will cause. 

Guilt-free Leave - Company policy that tells staff not to bring work with them on their holidays and not to take phones lap-tops, etc.

Gung holier than thou/ Gung holiness - An unquestioning sense of moral right allied to a martial attitude and plenty of military hardware.