Wiktionary
fag out
vb. To become untwisted or frayed, as the end of a rope, or the edge of canvas.
WordNet
Usage examples of "fag out".
I grind the fag out in the ashtray and cough a bit and then look at the cigarette packet.
But Dinger, the model diplomat, every time the major turned up now hed get a fag out of him.
He touched up some female in the pictures and she gave him a different sort of thrill from what he expected by stubbing her fag out on his hand.
This one blacked his shoes: that toasted his bread, others would fag out, and give him balls at cricket during whole summer afternoons.