“Ambiguous: Having two or more meanings. Defined as a property of sentences or utterances: I filled the pen is thus ambiguous, as a whole, in that the pen may refer to a writing instrument or to an enclosure for animals. Most accounts distinguish lexical ambiguity, due as in the example to the different meanings of lexical units, from grammatical or syntactic ambiguity. For the latter compare e.g. I like good food and wine, where good could relate syntactically to either food alone or to both food and wine; what is liked would correspondingly be good food and any wine whatever, or good food and wine that is also good.
Many linguists will talk of ambiguity only when it can be seen, as in these examples, as inherent in a language system. It can thus be defined as a property of sentences, independent of the contexts in which they are uttered on specific occasions. Other linguists will distinguish semantic ambiguity, as ambiguity inherent in a language, from pragmatic ambiguity. But what exactly is inherent in a language is as problematic here as elsewhere.”
Excerpted from: Matthews, P.H., ed. The Oxford Concise Dictionary of Linguistics. New York: Oxford University Press, 2014.