moldy

adjective

ˈmōl-dē 

moldier; moldiest

1

: of, resembling, or covered with mold

2

a

: being old and moldering : crumbling

b

: antiquated, fusty

moldy tradition

moldiness noun

Examples of moldy in a Sentence

Her books became moldy after being left in a damp basement.

The wine had a slightly moldy aroma.

Recent Examples on the Web

But when in doubt, throw moldy cheese out. —Abby Norman, Verywell Health, 29 Sep. 2025

That brown bottle in your medicine cabinet can clean moldy bathrooms and kitchens. —Karen Brewer Grossman, Southern Living, 27 Sep. 2025

Dilute bleach with water in a spray bottle and use it to saturate the moldy spots along the caulking. —Mary Cornetta, Better Homes & Gardens, 23 Sep. 2025

Nearly 100 years ago, in 1928, Scottish physician Alexander Fleming famously noticed that, in a moldy Petri dish, Penicillium notatum had destroyed the bacteria around it (even if penicillin would still be more than a decade away from development). —New Atlas, 20 Sep. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for moldy

• mouldy
• soldi

Kids Definition

moldy

adjective

ˈmōl-dē 

moldier; moldiest

: resembling, containing, or covered with mold

moldiness noun

Medical Definition

moldy

adjective

variants or chiefly British mouldy

ˈmōl-dē 

moldier or chiefly British mouldier; mouldiest

: covered with a mold-producing fungus

moldy bread