recognise in WordNet English dictionary

1. grant credentials to
   "The Regents officially recognized the new educational institution"; "recognize an academic degree"
   accredit  recognize  recognise 
   
2. accept (someone) to be what is claimed or accept his power and authority
   "The Crown Prince was acknowledged as the true heir to the throne"; "We do not recognize your gods"
   acknowledge  recognize  recognise  know 
   
3. express obligation, thanks, or gratitude for
   "We must acknowledge the kindness she showed towards us"
   acknowledge  recognize  recognise 
   
4. be fully aware or cognizant of
   recognize  recognise  realize  realise  agnize  agnise 
   
5. detect with the senses
   "The fleeing convicts were picked out of the darkness by the watchful prison guards"; "I can't make out the faces in this photograph"
   spot  recognize  recognise  distinguish  discern  pick out  make out  tell apart 
   
6. express greetings upon meeting someone
   greet  recognize  recognise 
   
7. perceive to be the same
   recognize  recognise 
   
8. show approval or appreciation of
   "My work is not recognized by anybody!"; "The best student was recognized by the Dean"
   recognize  recognise 
   

recognise in English Wiktionary