こたい固体kotai
1.

A state of matter characterized by a definitive shape and volume, which does not easily change under normal conditions.

2.

A type of material in which the arrangement of atoms or molecules is typically orderly, resulting in a rigid structure, as opposed to gaseous or liquid forms.

3.

A form of substance that maintains its shape and size, featuring a structure that can be categorized into crystalline solids with regular atomic arrangements and amorphous solids without such order.

Example:

固体が解けると液体になる。

こたい固体kotaiロケットroketto
1.

A type of rocket that utilizes a solid propellant composed of both fuel and oxidizer to generate thrust and achieve flight.

2.

A rocket engine system that relies on a pre-combusted solid material for propulsion, contrasting with liquid-fueled rockets.