Also an abbreviation for Foiled Twisted Pair, a type of network cable where the signal cables have been insulated by a strip of aluminium foil, wrapped in a spiral. Confusing the hell out of LAN technicians, I'll bet you.

This type is cheaper than proper STP, but more susceptible to mechanical wear, making it a bad choice for patch boards.

Buying bulk Ethernet cable from clueless induhviduals often gets you FTP when you've specifically asked for proper STP, prompting the following exclamation:
Curses! Foiled again!