A word, phrase, or sentence is ambiguous if it has more than one meaning. The word 'light', for example, can mean not very heavy or not very dark. Words like 'light', 'note', 'bear' and 'over' are lexically ambiguous. They induce ambiguity in phrases or sentences in which they occur, such as 'light suit' and 'The duchess can't bear children'. However, phrases and sentences can be ambiguous even if none of their constituents is. The phrase 'porcelain egg container' is structurally ambiguous, as is the sentence 'The police shot the rioters with guns'. Ambiguity can have both a lexical and a structural basis, as with sentences like 'I left her behind for you' and 'He saw her duck'.