homonym

n. word that is identical in spelling and pronunciation to another word but has a different meaning

For the specialised use of homonym in scientific nomenclature, see Homonym (botany) and Homonym (zoology).In linguistics, a homonym is one of a group of words that share the same spelling or pronunciation (or both) but have different meanings. The state of being a homonym is called homonymy. Examples of homonyms are stalk (which can mean either part of a plant or to follow someone around) and the trio of words to, too and two (actually, to, to, too, too and two, being "for the purpose of" as in "to make it easier", the opposite of "from", also, excessively, and "2", respectively). Some sources state that homonym meanings must be unrelated in origin (rather than just different). Thus right (correct) and right (opposed to left) would be polysemous (see below) and not be homonyms.
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Noun
1. two words are homonyms if they are pronounced or spelled the same way but have different meanings
(hypernym) word
(hyponym) homograph

n. homonym, word that is identical in spelling and pronunciation to another word but has a different meaning

(n.)
A word having the same sound as another, but differing from it in meaning; as the noun bear and the verb bear.