Something that you may call someone but not necessarily want them to know you said it.
For example, "Call him shinzlefonze... but don't tell him I told you to write it."
The term can be either derogatory or complimentary in nature, and this is generally determined by the preceeding conversation and the tone of voice. It becomes much more derogatory in the -fonze ending is replaced by a profanity.
For example - "Call him shinzlepiss."
The word is thought to originate in Malia, Greece in late August 2005 where it was adapted for everyday use (especially when drunk) by three Northern Irish guys on holiday there. One of the three was seen wearing a t-shirt with the word printed on the back and is sometimes thought to be the main fore-runner of the three in bringing the word to the masses. There is also some anecdotal evidence that the word is partly derived from a David Firth cartoon called "Burnt Face Man" in which one of the leading antagonists is heard to say, "Call him pisslips, but don't tell him I told you to write it" but the link, at present, is tenuous.
The word is increasing in prevalance, being heard uttered in Belfast, Ballymena, Portstewart and Kells as the student population takes the word as it's own.