pack heat To carry a gun. Ejem: Be careful when you're out late at night -- you never know who might be packing heat.

Ejem2: You never had to tell Dirty Harry to pack heat - he was always carrying a .44 Magnum.

Explanation: "Heater" is slang for a gun, and "pack" means 'a container' or 'to fold up' or 'to put away'. So when you "pack heat" you become a container for a gun - or put a gun on your body, in your clothes.

go ballistic To get very angry; to become enraged. EJem: Don't tell Tom that you scratched his car - he'll go ballistic!.

You can also say: go ape.

pink slip Notice of termination of employment; a note from your employer telling you that you've lost your job. Ejem: I think our boss enjoys handing out pink slips. Ejem2: The factory is closing next week, and all 500 employees received pink slips today.

Explanation: In the 1920's, large corporations developed color-coded paper communication systems. Pink paper was used to send the message "you're fired."

click and mortar: A business that combines traditional retail sales and on-line marketing. Ejem: Barnes and Noble is a major click and mortar book seller.