twig

Noun

• a small branch or division of a branch (especially a terminal division); usually applied to branches of the current or preceding year

Verb

• understand, usually after some initial difficulty
  • She didn't know what her classmates were plotting but finally caught on
    

• branch out in a twiglike manner
  • The lightning bolt twigged in several directions
    

Related words

• Synonyms: 
  branchlet , sprig , catch on , get wise , get onto , tumble , latch on , cotton on , get it