What does brittle mean?
Brittle describes materials that are hard and rigid yet break or shatter easily when struck, bent, or stressed, rather than deforming gracefully like metal or rubber. Glass, dried clay, and autumn leaves are classic examples. The word extends naturally into human territory: a brittle person may seem composed or even sharp-tongued on the surface while hiding emotional fragility underneath, and we speak of brittle peace agreements or brittle economies poised to collapse. This figurative sense gives the word real expressive power, letting writers convey tension and vulnerability in a single stroke. In science and engineering, brittleness is a formal property contrasted with ductility and toughness, appearing in fields from metallurgy to medicine, as in osteoporosis, historically called brittle bone disease. Derived forms such as brittleness keep the concept useful across everyday, literary, and technical registers alike.
Hard but liable to break, crack, or shatter easily rather than bend; figuratively, outwardly firm but emotionally fragile.
"The ceramic glaze had become brittle with age, flaking away at the slightest touch."
Most commonly applied to rigid solids; the figurative sense usually carries a tone of concealed vulnerability.
In materials science, the quality of being brittle — a tendency to fracture without significant deformation.
"The engineer noted the alloy's excessive brittle, which made it unsuitable for structural beams."
Rare in general usage; 'brittleness' is the far more common noun form.
Before modern spelling settled down, 'brittle' was sometimes written 'bretel' — but its core idea hasn't shifted in over a thousand years: things that snap instead of bend.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of brittle
'Brittle' descends from Old English 'brytel', meaning fragile or easily broken, which derives from a Germanic root connected to breaking. The word has remained remarkably stable in both form and meaning throughout its recorded history in English. Its core sense — something that breaks rather than bends — has persisted unchanged for over a millennium, making it one of the more durable descriptive terms in the language.
Related word forms
How brittle is actually used
Primarily an adjective describing physical materials (glass, ceramics, dry leaves), but widely extended figuratively to describe emotional fragility or strained situations, often with a slightly literary or dramatic connotation. In technical writing, especially metallurgy, 'brittle' contrasts with 'ductile' or 'malleable'.
Easily confused with brittle
Bristle refers to stiff hairs or short stiff fibers (or, as a verb, to react with anger), whereas brittle means easily broken.