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

A chip yield refers to the amount of usable chips that come from one wafer.

From MarketWatch • May 15, 2026

The company has pioneered wafer-scale chips, meaning a chip that takes up the entire silicon wafer that is normally cut up into many smaller processors.

From The Wall Street Journal • May 15, 2026

Companies like semiconductor equipment maker Tokyo Electron and silicon wafer giant Shin-Etsu Chemical have kept stock indexes buoyant and powered a 12% jump in exports year over year in the first quarter of 2026.

From Barron's • May 14, 2026

Included in the guidance is an additional $30 million in costs for an extended maintenance shutdown at its solar wafer facility, it said.

From The Wall Street Journal • Apr. 28, 2026

A wafer of a moon was shining over Gatsby's house, making the night fine as before and surviving the laughter and the sound of his still glowing garden.

From " The Great Gatsby" by F. Scott Fitzgerald

Related Words

• biscuit
• cake
• candy
• cookie
• cracker