1.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
2.be fully aware or cognizant of
3.detect with the senses;
The fleeing convicts were picked out of the darkness by the watchful prison guards
4.perceive to be the same
5.grant credentials to;
The Regents officially recognized the new educational institution
6.express greetings upon meeting someone
7.express obligation, thanks, or gratitude for;
We must acknowledge the kindness she showed towards us
8.exhibit recognition for (an antigen or a substrate)
9.show approval or appreciation of;
My work is not recognized by anybody!