paravane
noun
para·vane ˈper-ə-ˌvān 
ˈpa-rə-
: a torpedo-shaped protective device with serrate teeth in its forward end used underwater by a ship in mined areas to sever the moorings of mines
Word History
Etymology
probably from French para- warding off (as in parachute) + English vane
First Known Use
1919, in the meaning defined above