Adhil is Xi Andromedae, a faint star of about fourth to fifth magnitude at roughly 200 light years, an orange giant that has evolved off the main sequence. It is not a conspicuous object, and its interest is chiefly in its name: Adhil comes from the Arabic al-dhayl, the train or skirt, marking its place on the trailing hem of the robe of Andromeda, the chained princess of the constellation. It is one of a number of dim stars that carry a traditional name out of all proportion to their brightness, the name preserving an old mapping of the human figure onto the stars.
Orange giants like Adhil represent a common evolutionary stage: a star that has exhausted the hydrogen at its core, begun fusing hydrogen in a shell around an inert helium core, and swollen and cooled as a result, a phase the Sun itself will pass through in several billion years. At fourth to fifth magnitude and roughly two hundred light years away, Adhil is bright enough to have been catalogued individually since antiquity but never bright enough to draw sustained attention. Adhil's designation as Xi Andromedae under the Bayer system places it well down the Greek-letter sequence, a rough but not perfectly reliable guide to relative brightness within a constellation that nonetheless correctly signals how minor a star this is.
Sources Star Names: Their Lore and MeaningRichard Hinckley Allen with AstronomyAndrew Fraknoi, David Morrison, and Sidney C. Wolff (OpenStax)