Defn: A genus of bivalve shells of which one species (D. polymorpha) is often so abundant as to be very troublesome in the fresh waters of Europe.

DRENCH
Drench, v. t. [imp. & p. p. Drenched; p. pr. & vb. n. Drenching.]
Etym: [AS. drencan to give to drink, to drench, the causal of drincan
to drink; akin to D. drenken, Sw. dränka, G. tränken. See Drink.]

1. To cause to drink; especially, to dose by force; to put a potion down the throat of, as of a horse; hence. to purge violently by physic. As "to fell," is "to make to fall," and "to lay," to make to lie." so "to drench," is "to make to drink." Trench.

2. To steep in moisture; to wet thoroughly; to soak; to saturate with water or other liquid; to immerse. Now dam the ditches and the floods restrain; Their moisture has already drenched the plain. Dryden.

DRENCH
Drench, n. Etym: [AS. drenc. See Drench, v. t.]

Defn: A drink; a draught; specifically, a potion of medicine poured
or forced down the throat; also, a potion that causes purging. "A
drench of wine." Dryden.
Give my roan horse a drench. Shak.

DRENCH
Drench, n. Etym: [AS. dreng warrior, soldier, akin to Icel. drengr.]
(O. Eng. Law)

Defn: A military vassal mentioned in Domesday Book. [Obs.] Burrill.

DRENCHE
Drench"e, v. t. & i.

Defn: To drown. [Obs.]
In the sea he drenched. Chaucer.