The act of climbing an object (wall, tree, fence, pile of junk, etc.), stopping at anytime and staying completely motionless (except for your tounge) while keeping from laughing or smiling. You have to commit.
Woah! That lady is lizarding that brick wall like no other!
The act of sticking one's tongue in and out rapidly to greet another individual in the hopes of getting him or her to lizard you back. Used as a way to greet someone to say hello or goodbye. Depending on the person, you may stick your tongue out as many times as you want and as fast as you want.
Larry spotted Zoey across the bar, but the music was too loud to shout hello and the room was too crowded to wave. Instead, Larry used the act of lizarding to attract Zoey and in return she started lizarding back. They were good friends.