arugula

A Mediterranean plant (Eruca vesicaria subsp. sativa) having flowers with purple-veined, yellowish-white petals and pungent, edible leaves. Also called rocket, rocket salad, Also called roquette.

[Probably Italian dialectal, from Latin ērūca, cabbage.]

[ah-ROO-guh-lah] Also known as Italian cress, rocket, roquette, rugula and rucola, arugula is a bitterish, aromatic salad green with a peppery mustard flavor. Though it has long been extremely popular with Italians, American palates often find its flavor too assertive. Arugula (which resembles radish leaves) can be found in specialty produce markets and in some supermarkets. It's sold in small bunches with roots attached. The leaves should be bright green and fresh looking. Arugula is very perishable and should be tightly wrapped in a plastic bag and refrigerated for no more than 2 days. Its leaves hold a tremendous amount of grit and must be thoroughly washed just before using. Arugula makes a lively addition to salads, soups and sautéed vegetable dishes. It's a rich source of iron as well as vitamins A and C.

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The noun has one meaning:

Meaning #1: erect European annual often grown as a salad crop to be harvested when young and tender
  Synonyms: rocket, roquette, garden rocket, rocket salad, Eruca sativa, Eruca vesicaria sativa