What is a material that is shaped when soft and then hardened referred to as?

The term for a material that is shaped when soft and then hardened is indeed plastic. This is because plastics are typically polymer materials that can be molded into various shapes while in a malleable state. Once shaped, they undergo a process of cooling or curing, during which they harden into a solid form. This characteristic of being easily shaped at high temperatures and then solidifying makes plastics highly versatile and widely used in various applications ranging from packaging to durable goods.

Other materials listed do not quite fit this definition in the same context. Textiles, while they can be manipulated, are primarily woven or knitted fibers and do not undergo a hardening process in the same manner. Glass, though it can be shaped when molten, typically involves a different process called forming and is not classified as a soft material that hardens after being molded in the usual sense associated with plastics. Wood, on the other hand, is a natural material that does not take on a soft state in the same way; it can be cut or shaped, but it does not undergo a hardening process akin to what happens with plastics.