jams

¹ American

[jamz] / dʒæmz /

noun

(used with a plural verb)

Informal. pajamas.

Jams ² American

[jamz] / dʒæmz /

Trademark.

a brand of baggy, brightly patterned, knee-length swim trunks.

Usage

What does jams mean? Jams is a very informal word for pajamas—the clothes you wear to sleep in. The word jammies means the same thing but is more common. Terms like jammies, jams, and jam-jams are typically used by children, adults speaking to children, or people using childish words to be silly. A more common synonym for pajamas is p.j.’s, which is informal but not as informal as jammies. You could say that whatever clothes children change into before going to bed are their jams. Traditionally, though, the word refers to clothes that were specifically made and sold for sleeping in, typically consisting of soft, loose-fitting pants or shorts and a (sometimes matching) top. When adults use the words jams or jammies to refer to what they’re wearing, it’s usually to refer to clothes worn for sleeping, but not always. People sometimes use such terms to refer to the clothes they wear to lounge in, especially before bed, though the terms p.j.’s and pajamas are more likely to be used this way. In all cases, the word jams is used very informally. The word jams is also the plural of the noun jam or a present-tense version of the verb jam, both of which have many meanings. Example: OK, kids, time for bed—go brush your teeth and change into your dinosaur jams.

Etymology

Origin of jams

First recorded in 1965–70; by shortening

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

When agents moved in perfectly straight paths, they quickly formed dense clusters and traffic jams that halted progress.

From Science Daily • Apr. 15, 2026

An alternative to jams or jellies, we love spooning it onto bites of toasted bagels or hot buttered toast.

From Salon • Apr. 13, 2026

Many shops were closed and outdoor cafes were packed in upscale neighbourhoods, as Tehran's legendary traffic jams vanished on Wednesday.

From Barron's • Apr. 8, 2026

In 2025, Meghan pivoted to consumer products, launching As Ever, an online marketplace of jams, dried flowers and other home goods that she started with help from Netflix employees.

From The Wall Street Journal • Mar. 11, 2026

The girl behind me jams her knees into my back.

From "Speak" by Laurie Halse Anderson

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023