We don't have synonyms for merica yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are erica, America and Myrica.
(n) :
Pronunciation spelling of America, representing clipped, perhaps dialectal, speech. [A supercontinent consisting of North America, Central America and South America regarded as a whole; in full, the Americas.]
(n) :
Alternative form of 'Murica. [(satirical, humorous, derogatory) The United States of America as viewed by the stereotypical southerner or conservative.]
(n) :
Pronunciation spelling of America, representing clipped, perhaps dialectal, speech. [A supercontinent consisting of North America, Central America and South America regarded as a whole; in full, the Americas.]
(n) :
Alternative form of 'Murica. [(satirical, humorous, derogatory) The United States of America as viewed by the stereotypical southerner or conservative.]