Euphemism for dissembling, spouting nonsense and red herrings or general bullshitting.
"Blowing smoke about forecast uncertainty and drawing absurd inferences is not helpful", said the commentator about Senator Larry Lindsey.
Trying to pretend like you're more important than you are or know something you really don't understand.
"He's just blowing smoke"
someone who is a big 'liar liar pants on fire'!
smoke blower: So sorry dude, I have to go to an emergency meeting at the Church of the Flying Spaghetti Monster and had to cancel my flight to Sydney.
me: ok no worries, lets reschedule for next month.
smoke blower: Facebook check in 'arrived at Sydney Airport today at 10:20am'.
me: oh, he's totes blowing smoke.
It means to leave a situation, such as the pub or workplace.
Its a technique used in the army to leave a situation under the cover of a smokescreen. Usually during tank manoeuvres.
"Right, I'm blowing smoke."
"What time are you blowing smoke?"
"in about 15 minutes."