What does mouldy mean?
Mouldy means covered with or spoiled by mould, the fuzzy growth that develops on damp, ageing, or poorly stored food and other organic material. In its literal sense, the word describes both the visible growth and the condition of the affected object: mouldy bread, mouldy cheese, or a cellar with a mouldy smell. It can also be used figuratively for something that seems stale, dull, decayed, or no longer fresh and energetic. This figurative use often carries a strongly critical or disparaging tone and may suggest that an idea or institution has become outdated or ineffective. Mouldy is the usual British spelling, while moldy is the standard American form. The word is especially useful when discussing food spoilage, damp storage, hygiene, and the small but unmistakable sensory clues by which decay first becomes apparent.
Covered with or affected by mould; decayed or spoiled as a result.
"They discarded the mouldy vegetables and cleaned the refrigerator thoroughly."
The literal sense is common in food safety, household care, and descriptions of damp or poorly stored materials.
Figuratively stale, dull, or lacking in freshness, vigour, and vitality.
"The performance was described as mouldy and utterly predictable."
This figurative use is more strongly evaluative and often appears in formal criticism or dismissive speech.
Mouldy begins with a subtle change in smell or texture, often giving a food's hidden decay its first unmistakable warning.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does mouldy come from?
Mouldy was formed in English by adding the suffix -y to mould, the spelling now used chiefly in British English. Mould itself ultimately comes through Old French from Latin mollis, meaning “soft,” although its later sense for the fungal growth developed independently along older Germanic and Romance usages. The American spelling mold reflects the usual simplification of British -ou- to -o-.
Related word forms
How mouldy is actually used
Mouldy is the standard British spelling; moldy is standard in American English. The figurative sense is less common than the literal one and may sound dated or strongly disparaging, especially when describing an idea, performance, or institution.
Easily confused with mouldy
Musty describes an unpleasant stale smell or quality, whereas mouldy specifically indicates growth caused by mould.
Mould is the fungus or the process of spoilage, while mouldy is the adjective describing something affected by it.