Due to the abstract nature of the signifier/signified relationship, a free-standing signifier is unable to convey knowledge or understanding by itself. After all, the only reason any word means what it means at all is due to a consensus of understanding by the wider community. Expanding on Saussure's own example of the arbitrariness of the word "tree", or any word for that matter, it can be seen that the word "tree" by itself could mean just about any upright bit of wood with branches, whether it grows leaves or provides a place to hang cups or hats.