turk's-cap lily \ˈ ̷ ̷ˌ ̷ ̷-\noun alsoturk's cap Usage: usually capitalized T : either of two lilies having nodding flowers with strongly revolute perianth segments: a.: a widely cultivated lily (Lilium martagon) with rather small dull purple flowers b.: an American native lily (Lilium superbum) with flowers resembling those of the tiger lily