Simple past and past participle of to flank.(verb)
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Use "flanked" in a sentence
"After advancing about 100 meters, it became obvious that high ground to the north and south meant their western line of advance could be flanked from the high ground on both sides."
"A stag flanked by two female red deer, or "hinds," trotted down a steep moorland pasture toward a wood."
"An oft-referenced chapter of the showdown played out from 1978 to 1980, a three-year time frame in which a pair of Demon state titles flanked a 1979 championship for the Sailors."