Pakkun is a way to shorten Patorikku-kun (The Japanese for Patrick) and is used as a nickname.
-Kudasai. Pakkun desu.
To agree to meet somewhere, but never show up or call to say that you won't be showing up.
Alli: Where was Brad last night? He totally missed out on the party.
Alex: I don't know. He said he was coming. He just totally Pakkuned.