flank noun

ADJ. left, right | north, northern, etc. | lower the lower flanks of Vesuvius | mountain

VERB + FLANK attack They decided to attack their enemy's southern flank. | defend, protect | expose West Ham exposed the right flank of Norwich's defence (= showed that it could be attacked easily).

FLANK + NOUN attack

PREP. along a/the ~ along the eastern flank of Greenland | down the ~ a beautiful pass down the right flank | on a/the ~ The army was attacked on the left flank.