When a person is always running late or always late.
Heaven Lara is a Lagger-bitch, but shes almost here.
A person who can slow down or "Lag" their digestive system so they can't crap for very long periods of time.
Jon: "dude, I just found out that I am an Anal Lagger"
Xavier: dude that is freakin' amazing, can you teach me?
Jon: no.