What is Creaseless?

Creaseless definition and meaning on Dictionary terms:

a ridge or groove produced in anything by folding, heat, pressure, etc.; fold; furrow.
a wrinkle, especially one on the face.
the straight, vertical edge or line produced in the front and back of trousers, especially men’s trousers, by pressing, as with a steam presser or iron.
Ice Hockey. the marked rectangular area in front of each goal cage, into which an offensive player can skate only if that player has the puck, if the puck is already within the area, or if the goalie is absent.