Lexical ambiguity is the potential for multiple interpretations of spoken or written language that renders it difficult or impossible to understand without some additional information. The ambiguity typically results from the fact that words can mean different things; the additional information typically supplies context that clarifies which meaning is intended in this instance. Lexical means related to words, from the Greek lexikos.
Lexical ambiguity is what makes puns and other types of wordplay funny, and unintentional humor can occur when words aren’t considered carefully enough. For example, the Columbia Journalism Review once published a collection of ambiguous headlines, such as “Red Tape Holds up New Bridge.” The ambiguity there results from the fact that holds up can mean both delays and supports, and the humor comes from the fact that the idea of holding a bridge in place with red tape is ridiculous. Headlines rendered difficult to parse because of ambiguity are sometimes known as crash blossoms, so-named for one that appeared in Japan Today: “Violinist Linked to JAL Crash Blossoms.”
Lexical ambiguity is often contrasted with structural or syntactic ambiguity, which complicates the interpretation of written or spoken language because of the way in which words or phrases are arranged. Linguistic ambiguity, which includes both of these as well as other categories, is a particular problem for natural language processing (NLP) programs. Word sense disambiguation (WSD) is an essential component of speech recognition, text analytics and other language-processing applications.