I. ˈflaŋk noun
Etymology: Middle English, from Old French flanc, of Germanic origin; akin to Old High German hlanca loin, flank — more at lank
Date: before 12th century
1.
a. : the fleshy part of the side between the ribs and the hip ; broadly : the side of a quadruped
b. : a cut of meat from this part of an animal — see beef illustration
2.
a. : side
b. : the right or left of a formation
3. : the area along either side of a heraldic shield
II. transitive verb
Date: 1594
1.
a. : to be situated at the side of ; especially : to be situated on both sides of
a road flank ed with linden trees
b. : to place something on each side of
2. : to protect a flank of
3. : to attack or threaten the flank of (as a body of troops)