carrying a gun, often concealed
The off-duty policeman was packing.
gerundive form, by ellipsis from "to pack heat"
A method of network data transmission, in which small blocks of data, or packets, are transmitted over a channel which, for the duration of the packet's transmission, is dedicated to that packet alone and is not interrupted to transmit other packets. This strategy is used in transmitting data over the Internet and often over a LAN, and it capitalizes on the increase in efficiency that is obtained when there are many paths available and there is a large volume of traffic over these paths.