What does solid mean?
“Solid” describes something firm, compact, and substantial, as in a solid table or a solid wall. It can also indicate strength, stability, or reliability: a solid foundation, a solid partnership, and a solid performance all suggest qualities that are secure and dependable. When used of evidence or an argument, it means well-supported and convincing rather than merely plausible. As a noun, “solid” refers to a substance with a fixed shape and volume, or to a three-dimensional geometric form. The word is versatile in everyday and formal English, but its basic implication is that something is not hollow, flimsy, unstable, or incomplete. Its historical connection with the Latin solidus, meaning whole or complete, also explains its association with coherence and soundness.
Firm, compact, and without hollow spaces; stable, reliable, complete, or strongly supported.
"The report provides a solid basis for further investigation."
Commonly used for physical materials, but also metaphorically for foundations, evidence, arguments, and performance.
A substance that retains its shape and has a fixed volume; also, in geometry, a three-dimensional object extending in all directions.
"Water becomes a solid when it freezes."
The geometric sense is usually used in technical or educational contexts.
Used for separate solid substances or geometric objects.
"The experiment measured the density of several solids."
The word “solid” comes from Latin solidus, meaning whole or complete—a fitting origin for an idea that suggests firmness and reliability.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does solid come from?
The word comes from Latin solidus, meaning “whole,” “solid,” or “compact.” English borrowed it in the late Middle English period, initially for substances that were not hollow or fluid. The related English words “consolidate,” “solidity,” and “solder” reflect the same Latin root through later developments.
Related word forms
How solid is actually used
“Solid” is common in formal and informal English. In expressions such as “a solid performance,” it indicates dependable quality or strong support; “a solid hour” means a full, uninterrupted hour.
Easily confused with solid
“Solid” describes something firm or substantial, whereas “salad” is a dish of vegetables and other ingredients.
“Solid” is pronounced with an initial /s/ and has two syllables, while “souled” is pronounced /ˈsoʊld/ and means having a soul.