homonymy; homonymity
Technical term in linguistics and computing for the property of words that share the same written form and pronunciation but have different meanings.
Homonymy causes ambiguity in natural language processing.
同音異義語 refers to homophones (words with the same pronunciation but different meanings), while 同形同音異義性 is the abstract property of being both homographic and homophonic.
同形異義語 are homographs (same spelling, different meaning), but they may differ in pronunciation, unlike 同形同音異義性 which requires identical pronunciation as well.
Compound of 同形 (same form), 同音 (same sound), 異義 (different meaning), and 性 (property). A modern technical coinage.