A improperly used version
of the term "Snarf" which
refers to the small fluffy cat from from
80's television show "ThunderCats" that would commonly
say his name. Shnarf is said when someone would commonly
laugh and is usually purposely implied to something that is considered idiotic or obnoxious.
For those times when words like 69 appear, there are douche bags that will instinctively mutter "Shnarf" under their breathe. These
people will without question say "Shnarf" under any circumstance.