We don't have synonyms for overwind yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are overhand, overbid and overmind.
°To wind (tighten a spring of) something excessively.
"{{quote-news|year=1989|date=July 4|author=Jacquin Sanders|title=What makes a watchmaker tick?|work=St. Petersburg Times|url=http://news.google.com/newspapers?id=G_8NAAAAIBAJ&sjid=R3gDAAAAIBAJ&pg=2414,5286977&dq=overwind"
°To wind (tighten a spring of) something excessively.
"{{quote-news|year=1989|date=July 4|author=Jacquin Sanders|title=What makes a watchmaker tick?|work=St. Petersburg Times|url=http://news.google.com/newspapers?id=G_8NAAAAIBAJ&sjid=R3gDAAAAIBAJ&pg=2414,5286977&dq=overwind"