What does it mean if a solid is malleable?

Hint: There are special properties of some compounds that make them distinct. Malleability and ductility are the properties of metals. Malleable solid means that it can be converted into thin pieces of sheets. Only metals are capable of making them into thin sheets.

Complete answer:
Solids are the substances with a closed packed structure. The molecules are placed in certain geometry as they get some shape and structure with having magnitude and mass. Some solids possess properties like conducting heat and electricity, high tensile strength, malleability and ductility.
A solid is said to be malleable if it can be made into thin sheets. Usually metals possess the ability of being malleable. Metallic solids are made malleable by beating them with a hammer or by using rollers on them to make them into thin sheets. Malleability is possessed due to the metallic bonding of metals. As metals have free electrons the atomic layers are capable of sliding over each other. The free electrons in metals are displaced in a course of pressing the metal thereby delocalizing the electrons and making new bonds without breaking the metals. This involves the shift in the nucleus that allows the electrons to move freely and make new bonds.
Hence, a solid is said to be malleable if it can be made into thin sheets.

Note:
Metals being malleable can be ductile also. Ductility is the property to make a metal into thin wires. The most malleable metal is gold, that can be drawn into thin sheets, this property is used in making jewelry, while the most ductile metal is copper that is made into thin wires used in electrical circuits.