Solid
Solid explained in an easy to understand way:
Imagine trying to fit a large, bulky sofa through a narrow doorway when moving into a new apartment. Just like the sofa maintains its distinct shape and size regardless of how you try to maneuver it, a solid maintains its definite shape and volume irrespective of the space it occupies. In this analogy, the sofa represents a solid, with its unchanging dimensions symbolizing the fixed shape and volume characteristic of solid matter, while the doorway represents the space around it that does not alter the sofa's inherent properties.
Practice Version
Solid: The state of matter with definite shape and volume. Solid. Solids are materials whose molecules are packed closely together, giving them a fixed shape and volume.