Calling something "polyester" is a way of saying it looks flashy on the surface but is actually cheap, hollow or mass-produced. The insult borrows straight from the fabric's reputation: a petroleum-based synthetic that is durable and wrinkle-resistant but widely seen as low-quality and bad for the environment1. In fast fashion, polyester is the material of choice for churning out huge volumes of throwaway clothes2, and that connotation is doing all the heavy lifting in the slang.

On TikTok, the word is thrown at anything from a lifestyle to a merch drop to a whole style of video edit. USA Today described it as a jab at things that are "low-quality or cheap," tied to a wider Gen Z suspicion of polyester fabric compared with higher-blend cottons3. Streamers and influencers who sold 100% polyester merch, like LowTierGod (jokingly dubbed "the Polyester Prince"), had been mocked for years before the word broke through as generalized slang3.

People typically use "polyester" as a one-word verdict on something that tries to look expensive, deep or original but reads as cheap and mass-produced. Common conventions include tagging a flashy TikTok edit as "polyester," calling a scripted-sounding morning routine a "polyester lifestyle," or dunking on merch and outfits that scream fast fashion34. It often replaces older jabs like "cheugy" or "NPC" when the target is specifically about surface flash hiding low substance.