Those biscuits you used to eat when you were a kid, and you were amazed to stumble upon some re-packaged in the super market the other day when you were all grown up or find in your friends cupboard. Famous ones include the'nice' biscuits which were anything but nice, the ring shaped biscuits with multi coloured icing on that make your teeth itch and look like some acid trip induced creation from the 60's (and still do! including pink and brown colours!) and such things as Bourbons and custard creams can be considered 'retro'
"John, check out the retro biscuits Chris has in his cupboard"
A word used for a known quantative change derived from the word Delta which symbolised the fourth letter of the greek alphabet. This term or definition of this word is more commonly used in physics and engineering (and can be seen in the world of computer geeks), although somehow it's found it's way into the lame world of office lingo / office jargon.
Executives all around the world frequently misuse this term and it's misuse is growing, making them look very stupid.
Executive noob says "We have a delta in these figures here somewhere" secretery says "It's not a delta, it's a discrepancy" People then mock the executive noob behined his back while he thinks he's just impressed everyone by telling them that there is an identified change that has not actually been identified.