A person who (usually secretly) makes use of an unsecured wireless internet signal belonging to another entity. Also, one who hacks into or otherwise compromises a wireless network to in order to access free wireless internet. Contraction of "wireless pirate" and a play on the term "wi-fi."
"Any student living around campus can easily become a wi-pi, since the college neglected to password protect or encrypt their wireless network."
by MathewWebster September 25, 2007