What is define rigid?

Rigid is an adjective that is used to describe something that is stiff, unyielding, or inflexible. It can be used to describe materials, such as steel or concrete, that are difficult to bend, shape or compress. Rigid can also refer to the behavior or personality of a person who is resistant to change, stubborn or unyielding in their beliefs or opinions. In biology, rigid may be used to describe the structure of cells or tissues that are tough, like bones or cartilage, that support and protect organs. In engineering, rigid structures are often designed to provide stability and support, like bridges or buildings that withstand external forces or loads. In summary, rigid refers to something that is firm, unbending, and unyielding.