What is thneed meaning?

Thneed is a made-up word from Dr. Seuss' book "The Lorax." In the book, the Once-ler creates the thneed, a versatile garment that can be used as a sweater, a hat, a rug, and more. The thneed is made from the Truffula trees in the story and becomes a symbol of the Once-ler's destructive greed and the environmental devastation caused by consumerism. In popular culture, thneed has come to represent any product that is marketed as essential but is actually unnecessary or harmful to the environment.