At*ten`u*a"tion (&?;), n. [L. attenuatio: cf. F. atténuation.] 1. The act or process of making slender, or the state of being slender; emaciation.
2. The act of attenuating; the act of making thin or less dense, or of rarefying, as fluids or gases.
3. The process of weakening in intensity; diminution of virulence; as, the attenuation of virus.
At"ter (&?;), n. [AS. tter.] Poison; venom; corrupt matter from a sore. [Obs.] Holland.
At"ter*cop (&?;), n. [AS. attercoppa a spider; tter poison + coppa head, cup.] 1. A spider. [Obs.]