Definitions of dredge:

• noun:   a power shovel to remove material from a channel or riverbed
• verb:   remove with a power shovel, usually from a bottom of a body of water
• verb:   search (as the bottom of a body of water) for something valuable or lost
• verb:   cover before cooking

  Example: "Dredge the chicken in flour before frying it"

• name:  A surname (very rare: popularity rank in the U.S.: #38160)