Having the same spelling as another word but different meaning and pronunciation; being a heteronym, or relating to heteronymy.
From heteronym plus -ous (adjectival suffix), describing words that are heteronyms or the relationship between heteronymic words.
In physiology, there's also a sneaky meaning: nerve fibers that cross to opposite sides of the body are called heteronymous because they respond to stimuli from the 'other side'—same word, neuroscience twist!
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