The slang and the use of slang by a certain person or group of persons. Can be used in a posative or negative manner depending on the assessement of it quality in wit, humour, and mannerism. Scottish in orgin.
"That guys patter wis puremagic"
"That guys patter wis pure crap."
The practice of urinating on your school dean, without them knowing.
Your school dean comes up to you and your mates and starts to tell you off. So one of you moves behind him and starts to urinate on the back of his leg. The noise made is like a patter, hence the name.