Lewis & Short

pĕr-ăcūtus, a, um, adj., very sharp.

  1. I. Lit.: falx, Mart. 3, 24, 5 (dub.).
    1. B. Transf., of sound, very clear or penetrating: vox, Cic. Brut. 68, 241.
  2. II. Trop., very keen, very acute, very penetrating: cum peracutus esset ad excogitandum, Cic. Brut. 39, 145: oratio, id. ib. 76, 264; id. Verr. 2, 2, 44, § 108.
    Adv.: pĕrăcūtē, very sharply, very acutely, with great keenness: moveri, Cic. Ac. 1, 9, 35: peracute querebare, quod, etc., id. Fam. 3, 7, 2: reperisse, App. Mag. 34.