We don't have synonyms for try-hard yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are try hard and try hand.
(n) :
(derogatory) Alternative spelling of tryhard. [(informal, derogatory) A person usually of little talent who tries hard to succeed, especially through imitation, usually to gain fame or popularity.]
(n) :
(derogatory) Alternative spelling of tryhard. [(informal, derogatory) A person usually of little talent who tries hard to succeed, especially through imitation, usually to gain fame or popularity.]