To be Laughing and barfing at the same time.

Walking with a swagger or slight limp.

crappy immature mj buds ;
term coined by us locals here in Southern California for shitty immature herb

a good time, or a good idea

Larf is simply a playful way of spelling laugh. It's good to say that you "larfed" instead of laughed, because, well, laughed is plain and ordinary and is used for every day situations, while larf is the result of something more unexpected and spontaneous. This is the crux of larf's meaning. It is used mostly from unexpected and spontaneous moments.

British play on word, "laugh."

to laugh in olden times