What does 2.2 mean?

2.2 means two point two. It is a number between 2 and 3, closer to 2. You could think of it like two and two tenths (2 + 2/10). This is the same thing as two and one fifth (2 + 1/5), or eleven fifths (11/5). I hope I haven't just insulted some highly educated math major. Maybe you were referring to this use of 2.2: http://www.urbandictionary.com/define.php?term=2.2 Or a .22 could refer to a .22 caliber gun.