Definition of: wafer

(wā′fər) noun
1. A very thin crisp biscuit, cooky, or cracker; also, a small disk of candy.
2. Eccl. A small flat disk of unleavened bread stamped with a cross or the letters IHS, and used in the Eucharist in some churches; the sacred host.
3. A thin hardened disk of gelatin, flour, isinglass, or other suitable substance, used for sealing letters, attaching papers, or receiving the impression of a seal.
4. Med. a A thin double layer of dried paste enclosing a pill or capsule. b A suppository.
5. A disk of priming material used in early artillery.
—v.t. To attach, seal, or fasten with a wafer. [<AF wafre <MLG wafel. Akin to WAFFLE.]