What is stretch-in carpet with wrinkles called?

Stretch-in carpet that develops wrinkles is referred to as "buckled." This term describes a specific condition where the carpet material has not been properly tightened during installation or has experienced significant changes in temperature or humidity, causing it to lose its tension and create noticeable undulations or waves. Unlike other terms that may describe minor issues or different types of imperfections, "buckled" indicates a clear and specific problem related to the installation process and the carpet's adaptability to environmental changes. Addressing buckling typically involves re-stretching the carpet to restore its original flat appearance, ensuring it fits snugly against the floor and eliminating any looseness.