wafer

Concise Oxford English Dictionary © 2008 Oxford University Press:
wafer/ˈweɪfə(r)/

▶noun

• 1 a thin, light, crisp sweet biscuit.

• 2 a thin disc of unleavened bread used in the Eucharist.

• 3 a disc of red paper stuck on a legal document as a seal.

  ■ historical a small disc of dried paste formerly used for fastening letters or holding papers together.

• 4 Electronics a very thin slice of a semiconductor crystal used as the substrate for solid-state circuitry.

– derivatives
wafery adjective.

– origin ME: from an Anglo-Norman Fr. var. of OFr. gaufre (see goffer), from Mid. Low Ger. wāfel ‘waffle’; cf. waffle2.