Polysemy (/pəˈlɪsɪmi/ or /ˈpɒlɪˌsiːmi/;[1][2] from Ancient Greek πολύ- (polý-) 'many' and σῆμα (sêma) 'sign') is the capacity for a sign (e.g. a symbol, a morpheme, a word, or a phrase) to have multiple related meanings.
Some seemingly unrelated words share a common historical origin, however, so etymology is not an infallible test for polysemy, and dictionary writers also often defer to speakers' intuitions to judge polysemy in cases where it contradicts etymology.
Alan Cruse identifies three types of non-linear polysemy:[6] There are several tests for polysemy, but one of them is zeugma: if one word seems to exhibit zeugma when applied in different contexts, it is probable that the contexts bring out different polysemes of the same word.
This test again depends on speakers' judgments about relatedness, which means that it is not infallible, but merely a helpful conceptual aid.
Lexicographers define polysemes within a single dictionary lemma, while homonyms are treated in separate entries, numbering different meanings (or lemmata).
Psycholinguistic experiments have shown that homonyms and polysemes are represented differently within people's mental lexicon: while the different meanings of homonyms (which are semantically unrelated) tend to interfere or compete with each other during comprehension, this does not usually occur for the polysemes that have semantically related meanings.
Charles Fillmore and Beryl Atkins' definition stipulates three elements: (i) the various senses of a polysemous word have a central origin, (ii) the links between these senses form a network, and (iii) understanding the 'inner' one contributes to understanding of the 'outer' one.
[18][19] A notion related to polysemy is colexification – namely, the case when several meanings are expressed by the same word.