Lewis & Short

hŏlus (better than ŏlus; archaic he-lus; cf.: helus et helusa antiqui dicebant, quod nunc holus et holera, Paul. ex Fest. p. 100 Müll. A form, holu, anciently helu, can be inferred from helvola, helvella, and olvatum; v. Müll. Paul. ex Fest. p. 203, b), ĕris (gen. plur. holerorum for holerum, Lucil. ap. Non. 490, 25; dat. plur. holeris for holeribus, Cato, R. R.), n. [Sanscr. haris, green; Gr. χλόη; cf.: helvus. helvola, Helvius; O. H. Germ. grucni; Germ. grün; Engl. green, etc.].

  1. I. Kitchen or garden herbs of any kind; vegetables, esp. cabbage, colewort, turnips, greens, Varr. R. R. 1, 16 fin.; Col. 2, 10, 22; Verg. G. 4, 130: pomum, holus, ficum, uvam, Afran. ap. Macr. S. 2, 16: donec Discoqueretur holus, Hor. S. 2, 1, 74: prandere, id. Ep. 1, 17, 13: silvestre, Plin. 22, 22, 38, § 80: marinum, sea-cale, id. 29, 4, 25, § 80: semper holus metimus, Calp. Ecl. 2, 74: Syria in hortis operosissima, venitque in proverbium Graecis, multa Syrorum holera, Plin. 20, 5, 16, § 33.
    Prov. for a coarse or humble meal, plain diet: melius est vocari ad olera cum caritate quam ad vitulum saginatum cum odio, Vulg. Prov. 16, 17: qui infirmus est olus manducet, ib. Rom. 14, 2.
  2. II. Holus atrum, also joined into one word, holusatrum (in gen. holeris atri and holusatri), n., a plant, called also Smyrnium holusatrum, Linn.; Col. 11, 3, 18; id. 12, 7, 1; Plin. 19, 8, 48, § 162; id. 19, 12, 62, § 187; called also: holus pullum, Col. 10, 123.