look up any word, like tinder bombing:
 
1.
Starting to smoke a joint.
Hey man... lets blaze up...
by Alwin September 11, 2005
 
2.
When someone offers to smoke weed with you for no charge on your part.

also referred to as burn up, smoke up, etc.
Friend: Yo dude what's good? Come pick me up and I'll blaze up
You: Werd
by Jesusxox0 February 10, 2010