latch on in WordNet English dictionary

1. understand, usually after some initial difficulty
   "She didn't know what her classmates were plotting but finally caught on"
   catch on  get wise  get onto  tumble  latch on  cotton on  twig  get it 
   
2. adopt
   "take up new ideas"
   take up  latch on  fasten on  hook on  seize on 
   
3. take hold of or attach to
   "The biochip latches onto the genes"
   latch on 
   

latch on in English Wiktionary