Wiktionary
vb. (context idiomatic English) To speak with a lack of credibility, sense, purpose, or truth; to speak nonsense.
Usage examples of "blow smoke".
He could blow smoke in a rival's face without blackening his own teeth or shortening his breath.
As always, he was smoking a large cigar, and paused occasionally to blow smoke at the camera.
Wood elves were the most capricious of Tel'Quess, ever ready to test some new delight or enliven a party with a touch of intemperance, and he could easily imagine them becoming slaves to the pipe after seeing some human wizard blow smoke rings through a yellow-stained beard.
He had seen it blow smoke when it was upset, but there was never a hint of flame.
And Northern rejoicing might be a little muted - oh, they'd go into mourning for their hero, and Mr Emerson and Mr Longfellow would write odes to the saint departed, and the Secret Six (having disclaimed Brown faster than you can blow smoke) would beat their breasts in public and give thanks in private that dead men can tell no tales .
He put his head back to blow smoke at the tall ceiling and that made his throat look more than ever like the throat of a woman.
Lower, and Depape would have been able to blow smoke-rings through his own palm.