Elaine Showalter's 1979 article "Towards a Feminist Poetics" is considered a landmark in the history of feminist literary criticism. Its use of the term "poetics" is very much a product of the period in which it was written and the major trends in literary theory of that time.
The dominant form of literary theory in the 1970s was structuralism, which, as applied to literature, meant a systematic examination of the formal features of texts using concepts from Continental structuralist linguists such as Ferdinand de Saussure and Roman Jakobson. Within this context, a "poetics" is a systematic, quasi-scientific account of how literature functions, in particular its formal qualities and modes of discourse. Although some theorists restrict the term "poetics" to poetry, more commonly it refers to any form of comprehensive literary theory.
The origin of the term goes back to the Platonic school, in which the suffix "ike" was attached to abstract concepts to describe the science of studying those areas. Thus the study of what rhetors do was termed "rhetorike", the study of logic "dialectike", and of poetry "poetike". Thus Aristotle's book on poetry in Greek is titled "Peri [about] Poiêtikês [Poetics]". Because Aristotle's work was so influential, and covered a general theory of imitation by means of words, rather than just verse form, the adoption of the term poetics signals a systematic or comprehensive treatment of verbal artifacts.
Showalter herself, although using the term poetics in the title, actually took the position that much of "poetics" marginalized women, and thus preferred to coin a new label, “gynocritics”, to refer to her own project of feminist literary studies.