Pluth, Ed. Signifiers and Acts: Freedom in Lacan’s theory of the subject New York: SUNY Press, 2007.
Certainly, unlike a sign, a signifier is not fixed to a particular object, but in its inclusion withn a system of other signifiers there is still an extreme form of reference at work. A signifier’s reference is not to a specific object or to a specific sign but to all other signifiers, or to the mere fact that signifiers exist (26).
According to Lacan’s view, there are nothing but signifiers and signified effects in language (29).
The signifier then is a purely meaningless and purely differential unity, and … not self-sufficient but hyper-referential. As such, it is also distinguished from the sign, whose reference is more or less fixed.
Although Lacan rejects the Saussurean notion of the sign — a union of signifier and signified — this does not prevent him from granting that some sort of signified effect is an important aspect of language. Although there may never be a strict union of signifer and signified, signifiers, according to Lacan, give the impression that there is meaning somewhere, however elusive it may be. In fact, this is precisely what signifiers do: they give an impression of meaning. (30)
A signifier is, moreover, meaningless. Since Lacan rejects the notion that a signifier and signified (meaning) are united in a single unit, meaning is never ultimately pinned to a signifier. So whatever meaning is, it is not reducible to or identifiable with a particular signifier (30).
According to Lacan, signifiers generate a signified effect or meaning effect that cannot itself be situated within the order of signifiers.