to make oneself appear (to be (doing) something) either in play or to deceive others
fake, falsify
Cases of word usage
1) to pretend to be (another person) by using the same behaviour etc (impersonate)
2) to pretend to be ill etc in order to escape duty or work (malinger)
3) to pretend (to be in the condition mentioned) (sham)
4) to pretend to be, have or feel (something) (simulate)