Lewis & Short

1. rŭta caesa, v. ruo, P. a.

2. rūta, ae, f., = ῤυτή (cf. Varr. L. L. 5, § 103 Müll.), a bitter herb, rue.

  1. I. Lit., Cic. Fam. 9, 22, 3; Col. 11, 3, 38; 12, 7, 5; Plin. 19, 8, 45, § 156; 20, 13, 51, § 131; Ov. R. Am. 801; Mart. 11, 31, 17; 52, 8.
  2. * II. Trop., bitterness, unpleasantness: cras exspecto Leptam, ad cujus rutam pulegio mihi tui sermonis utendum est, Cic. Fam. 16, 23, 2.