(pronounced DIKE-sis) A deictic expression is one that has only one meaning but can refer to different entities within the same context. The referent of a deictic expression varies depending on the point of view of the speaker. Common examples of deictic expressions are I, you, here, tomorrow, and right and left.

When Jack and Jill are speaking and Jack says "I love you", the word "I" refers to Jack. When Jill utters the exact same sentence, however, the word "I" refers to Jill. The meaning of the deictic word "I" has not changed, only the entity to which it refers, since Jack and Jill have different points of reference.

One should be careful not to confuse deixis with ambiguity, which is when one expression has more than one meaning.