What does it mean when a guy gives you a head nod?

[iceskatingsweetie]

a guy walks by and nods his head at you like he's saying what's up...

Updates

+1 y

k thanks :D

[PoliticalPerson]

It's a universal signal for hello. Kinda like tipping your hat, without the hat part.

[blah52]

Its just like saying hey, nothing else is implied.

[stevo]

When I do it, I'm acknowledge the person, so yeah, I'm saying what's up.

[user12345]

it means he's trying to be cool.