Polysemy
WordNet
noun
(1) The ambiguity of an individual word or phrase that can be used (in different contexts) to express two or more different meanings
WiktionaryText
Noun
- The ability of words, signs and symbols to have multiple meanings.
- [...] polysemy, which is the greedy habit some words have of taking more than one meaning for themselves. Erin McKean, speech at TED.