noun

• (bodybuilding, slang) Somebody, or one of their body parts, not looking developed.
  "You need to find a source of motivation and play off of that. Whether it be the jock in high school that always called you fat, or the guy who picked on you and called you a twig."

verb

• (transitive) To beat with twigs.

verb

• (colloquial, regional) To realise something; to catch on; to recognize someone or something.
  "He hasn't twigged that we're planning a surprise party for him."
• (intransitive) To be realized and understood; to click.
  "Dries had told us to bring at least twenty litres of water because there was no water in camp and very few tourists stayed there. I knew I wouldn't get a shower for three days, but I wasn't worried about that. It hadn't twigged that the reason we needed to bring our own water was that the camp itself was a warzone."

verb

• (obsolete, Scotland) To pull
  "Frank shall twig your Nose from your Face"