Allusion
Etymology
From Latin allūsiō, "a playing with, a reference," from allūdere ("to play with, jest at"): ad- ("toward") + lūdere ("to play"), from lūdus ("game"). The playful root is telling — an allusion is a game of recognition, a wink that only works if the reader is in on it.
noun · /uh-LOO-zhun/
A brief, indirect reference to a person, work, or event the audience is expected to recognize.
What it names
The economy of nodding to something outside the text — "his Waterloo," "a Judas" — borrowing its whole weight of meaning in a single word.
Example
Naming the startup "Icarus" was an allusion no investor missed — and, it turned out, an accurate one.
Related idea
Citation names its source openly and in full; an allusion stays glancing and unattributed, relying on shared knowledge to land.