It means
the first thing that comes to your mind(usually
along the lines of sex,
alchol, drugs, weed, etc) It should be used when you want to do a combination of the previous things listed or if you want to do anything that will entertain.
Yo Lets get laddered tonight!
Dude I'm so laddered right now.
Yo I laddered that chick last night she was awesome.
Yo I got
weed in
my car wana go get laddered?