hang on in WordNet English dictionary

1. fix to; attach
   "append a charm to the necklace"
   append  tag on  tack on  tack  hang on 
   
2. be persistent, refuse to stop
   "he persisted to call me every night"; "The child persisted and kept asking questions"
   persevere  persist  hang in  hang on  hold on 
   
3. hold the phone line open
   "Please hang on while I get your folder"
   hang on  hold the line  hold on 
   

hang on in English Wiktionary