wafer

American  

[wey-fer] / ˈweɪ fər /

noun

1. a thin, crisp cake or biscuit, often sweetened and flavored.

2. a thin disk of unleavened bread, used in the Eucharist, as in the Roman Catholic Church.

3. a thin disk of dried paste, gelatin, adhesive paper, or the like, used for sealing letters, attaching papers, etc.

4. Medicine/Medical. a thin sheet of dry paste or the like, used to enclose a powder to be swallowed.

5. any small, thin disk, as a washer or piece of insulation.

6. Electronics. a thin slice of semiconductor used as a base material on which single transistors or integrated-circuit components are formed.

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verb (used with object)

1. to seal, close, or attach by means of a wafer or wafers.

   to wafer a letter.

wafer British  

/ ˈweɪfə /

noun

1. a thin crisp sweetened biscuit with different flavourings, served with ice cream, etc

2. Christianity a thin disc of unleavened bread used in the Eucharist as celebrated by the Western Church

3. pharmacol an envelope of rice paper enclosing a medicament

4. electronics a large single crystal of semiconductor material, such as silicon, on which numerous integrated circuits are manufactured and then separated

5. a small thin disc of adhesive material used to seal letters, documents, etc

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verb

1. (tr) to seal, fasten, or attach with a wafer

Other Word Forms

• wafer-like adjective
• waferlike adjective
• wafery adjective

Etymology

Origin of wafer

1350–1400; Middle English wafre < Middle Dutch wafer, variant of wafel waffle ¹

Explanation

A very thin, crispy cookie is called a wafer. Chocolate cream sandwiched with wafers is a delicious treat. In addition to a cookie, wafer can also refer to the thin bread used during the Christian ritual of Holy Communion. These wafers are small and round. The word is used for other thin, disc-shaped objects as well, like an electronic wafer, a circular sliver of material that helps form a circuit. But the most common meaning is still the original "thin cake of paste," from a root that wafer shares with waffle.

Example Sentences

That would be roughly equivalent to between 140 and 360 new fabs capable of making 50 wafer starts per month.

From MarketWatch • Mar. 23, 2026

These properties make metal-organic frameworks an ideal photoresist—that chemical layer on a silicon wafer that absorbs light to create the etched pattern of transistors and connections.

From The Wall Street Journal • Feb. 27, 2026

The light carves the pattern into material on the wafer called photoresist.

From The Wall Street Journal • Feb. 27, 2026

Production capacity is unlikely to shift significantly until mid-2027, when Micron begins wafer output from a $50 billion expansion of its facilities in Idaho.

From Barron's • Feb. 23, 2026

Mrs. Rimas cried at the mention of the wafer and the traditional Christmas blessing, “God grant that we are all together again next year.”

From "Between Shades of Gray" by Ruta Sepetys

Related Words

• biscuit
• cake
• candy
• cookie
• cracker