what’s pneumonics mean?

The word is “mnemonics”. It refers to a system or method (sometimes a ‘trick’ or sets of tricks) for remembering/memorizing things, such as a set of facts, list of dates, vocabulary words.

http://dictionary.reference.com/browse/mnemonics

Here’s a mnemonic for this particular question — remember that this word begins not with “p” but with “m” by connecting it with “Memory”.

A good example of one: I use this to remember the planets and their order. -My Very Educated Mother Just Served Us Nine Pizzas- My=Mercury V=Venus E=Earth J=Jupiter S=Saturn U-Uranus N-Neptune P=Pluto