noun

• (British, criminal slang) An armed robbery or robbery involving violence; also, theft.
  "'What's he do, Micky?' / 'Armed blags is what I hear – s'posed to be one or two nice little tucks down to him that he didn't go for. He keeps well active. Someone told me he's putting one together now.[…]'"

verb

• (transitive, British, criminal slang) To obtain (something) through armed robbery or robbery involving violence, or theft; to rob; to steal.

verb

• (transitive)
  "Can I blag a fag?"
• (transitive)
  "The newspaper is accused of blagging details of the prime minister’s flat purchase from his solicitors."
• (transitive)
  "‘For the first six years I was a total chancer,’ he [Alan McGee] said. ‘I blagged it. All I did was keep choosing the right band and try not to fuck it up too much, which I usually did. […] [N]obody taught me to run a record company and I’ve made millions of mistakes.’"
• (transitive)
  "He asks me afterwards if I realize what a lot of 'blagging' (bull) there is in his job. I reply, 'You blagging him or him blagging you?' / 'Oh no, blagging him,' he says. 'When you give him a ticket or something, you have to be nice to them.'"

adj

• (British, informal) Not genuine; fake.
  "You’re wearing a blag designer shirt!"