n, pl  -lies  :  a union of two or more digits that is normal in many birds (as kingfishers) and in some lower mammals (as the kangaroos) and that occurs in humans often as a hereditary disorder marked by the joining or webbing of two or more fingers or toes .
 
 
 
Similar sounding terms:  syn·dac·tyl  syn·dac·tyl·ia 
 
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