Definitions of recognize:

• verb:   detect with the senses
• verb:   show approval or appreciation of

  Example: "My work is not recognized by anybody!"

• verb:   exhibit recognition for (an antigen or a substrate)
• verb:   perceive to be the same
• verb:   be fully aware or cognizant of
• verb:   grant credentials to

  Example: "The Regents officially recognized the new educational institution"

• verb:   accept (someone) to be what is claimed or accept his power and authority

  Example: "We do not recognize your gods"

• verb:   express obligation, thanks, or gratitude for
• verb:   express greetings upon meeting someone