v. & n.
v. 1 tr. a (often foll. by up) bring up (lost or hidden material) as if with a dredge (don't dredge all that up again). b (often foll. by away, up, out) bring up or clear (mud etc.) from a river, harbour, etc. with a dredge. 2 tr. clean (a harbour, river, etc.) with a dredge. 3 intr. use a dredge.
n. an apparatus used to scoop up oysters, specimens, etc., or to clear mud etc., from a river or sea bed.
[ 15th-c. Sc. dreg, perh. rel. to MDu. dregghe ]