1)The act of making a guitar-playing motion with your hands, usually done while listening to music, while under the influence of alchohol, or both.
2)What people do when they can't play guitar, and want to look cool, but they just end up looking riduculous.
(Also known as air guitaring
1)Jason got so drunk at the party last night, that he started air guitaring to air guitar along to the music, and then barfed on the stereo.
2)Look at that loser over there, playing air guitar.