1. Allusion
A reference in a literary work to a person, place, or thing in history or another work of literature.

2. Allusion - 2
Specific examples of allusions can be found throughout Dante’s Inferno. In a passage, Dante alludes to the Greek mythological figures, Phaethon and Icarus, to express his fear as he descends from the air into the eighth circle of hell. He states:

3. Allusion 3
I doubt if Phaethon feared more - that time he dropped the sun-reins of his father's chariot and burned the streak of sky we see today -
or if poor Icarus did - feeling his sides unfeathering as the wax began to melt, his father shouting:  "Wrong, your course is wrong" (Canto XVII: ).

4. Allusion - 4
Allusion is used to explain or clarify a complex problem. Note that allusion works best if you keep it short and refer to something the reader / audience is familiar with, e.g.:
famous people
history
(Greek) mythology
literature
the bible