1) A name for the style of hair some people sport, usually spiked straight up to give the slight appearance of a pineapple.
2) A nickname for somebody who has said hair style, but others around him/her don't appreciate their existence.
1) Damn, where did he get his hair cut? That's some pure pineapple hair right there.
2) Ugh, look at Pineapple-hair over there, thinking he's better than everyone else. Let's show him what we think.