How to Say "a poser" in Spanish
The Spanish word for “a poser” is “cursi” — B2 level.
English → SpanishB2
nounB2informal
someone pretending to have higher status

Examples
Aquel grupo de cursis no paraba de hablar de sus viajes de lujo.
That group of posers wouldn't stop talking about their luxury trips.
Using it as a label
When used as a noun, it just needs an article like 'un' or 'una' before it to label the person.
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