In literary terms, the main function of allusion in poetry is that it uses a powerful word, phrase or cultural reference that readers should understand in order to simply portray a complex concept. Allusion specifically references people, places and things in history, literature and society for this purpose. In addition, allusion can be used in poetry to help with tone and poetic form.
Allusion is used significantly in war poetry to help portray writers' heavy emotions. In addition, allusion in poetry is commonly used to signify social situations. For example, a poet could refer to something as sick or twisted to convey problems in society. Allusion can even be used in poetic narrative to portray the self. Modernist poets, for example, believed that a person could find meaning and wisdom only in himself or herself, and they often used nature as a relevant allusion.
Intertextual references to other texts are also a factor of allusion in poetry. Many poets refer to classical texts in their literature. For example, in the poem Hugh Selwyn Mauberley, Ezra Pound's line "His true Penelope was Flaubert" refers to Penelope, Odysseus's wife in Homer's Odyssey, and suggests that Gustave Flaubert, a French symbolist, can live up to Mauberley's standards as a partner. Even classical poets used allusion in their work. For example, Dante Alighieri referred to mythological Greek figures as symbols of fear in Inferno.
Although allusions are brief, they are filled with important references. Poets can use allusion to help easily portray situations by referencing certain time periods and events. Allusions are also useful for poets who aim to conform to specific poetic form. An allusion in poetry is often only a few words long, so it can easily fit within the poem's rhythm as well as with its meter, whether iambic, trochaic or anapestic, for example. Thus, allusion in poetry can be used by poets to enrich both a poem's meaning and its sound and beat.
Overall, allusion can be used in poetry to easily convey a message to readers. Upon reading allusions, individuals will pick up on references from history, literary texts, religion, mythology and more, evoking mental images and stimulating their minds. They simplify what otherwise would have to be explained in possibly lengthy terms, significantly tightening up a part of a poem to make it clear and concise and, in turn, ensuring that the poet's rhythm is retained in the process. Many types of poets employ the function of allusion to attract and interest readers, often exciting their knowledge if they already know to what the term is referring and otherwise challenging them to read and learn more.