acumen

Etymology

Borrowed from Latin acūmen (“sharp point”).

noun

1. Quickness of perception or discernment; penetration of mind; the faculty of nice discrimination.
   No, no, my dear Watson! With all respect for your natural acumen, I do not think that you are quite a match for the worthy doctor. 1905, Arthur Conan Doyle, “The Adventure of the Missing Three-Quarter”, in The Return of Sherlock Holmes
   Why do you think he removes their skins, Agent Starling? Enthrall me with your acumen. 1991, Ted Tally, The Silence of the Lambs (motion picture), spoken by Hannibal Lecter (Anthony Hopkins)
2. (botany) A sharp, tapering point extending from a plant.
   The black star of the corolla, characteristic of the original form, the manyfloweredness of the inflorescence (often connected with [3]—4 whirls), upper leaves in the inflorescence, adpression of the acumina of the calyx, its size, the closely situated anthers, long pistils, the length of the pedicel above and below the articulation and the thickness of the pedicel dominate. 1930, Prilozhenie, page 519
   11. S. boyacense. Resembles S. Rybinii from which it is distinguished by the greater dissection of the leaves, the longer calyx acumens, smaller anthers and coloured corolla. 1956, S.M. Bukasov, Translation of THEORETICAL BASES OF PLAN BREEDING, page 6
   Finally, the acumina of all the narrowly lanceolate leaves of both species tend to be straight rather than curved. 1960, Svensk botanisk tidskrift, page 385
   Herbs with long creeping stolons; leaves with coarse white hairs, or glabrous. The arched corolla lobes and large acumens give the corolla a circular appearance with acumens standing out sharply from it. Corolla occasionally, however, substellate. 1978, chapter 2, in The Potato Crop: The scientific basis for improvement, page 30
   […] the stem leaves lack recurved serrations on the margins, the acumina of the branch leaves are usually distinctly dentate. 1986, The Journal of the Hattori Botanical Laboratory, page 449
   In our opinion, specimens of I. pilifera represent a robust expression of I. sinensis with many stem and branch leaves becoming strongly concave and broadly ovate to obovate in outline, thereby intensifying the abrupt contraction of the pilaferous acumens. It is best accepted as a variety of N. comes. The length of leaf acumens is another variable character expressed by Barbella amoena. Thus, it is also better combined with the var. pilifera as a synonym. 1990, Cryptogamic Botany, Volume 2, page 315
   They examined the characters that were used by Paris (1908) to distinguish C. japonicum Broth. ex Paris from C. tonkinense: “Les charactères invoqués par Paris [Rev. Bryol., p. 46, 1908) pour distinguer la plante du Tonkin de celle du Japon s’évanouissent à l’examen, …”, and stated that the acumina of the leaves are narrower, and that those of the amphigastria are narrower and longer in C. japonicum Broth. ex Paris than in C. tonkinense. 2002, Blumea Supplement, page 327
3. (anatomy) A bony, often sharp, protuberance, especially that of the ischium.
   The rostrum is the anterior extension of the carapace between the eyes. It ends in a more or less acute tip, or acumen, and may have a lateral spine on each side or bear a longitudinal keel (carina) on the dorsal surface. c. 1918, University of California, Pamphlets on Biology: Kofoid collection, Volume 1586, page 692
   DIAGNOSIS—Rostrum usually with marginal spines, tubercles, or angles at base of acumen, and rarely with low medina carina. 1981, Horton Holcombe Hobbs, The Crayfishes of Georgia: Issue 318 of Smithsonian contributions to zoology, Smithsonian Institution, page 486
   Variations.—Most specimens examined have concave rostral margins that taper to the acumen and the rostral length is greater than the rostral width. 1993, Biological Society of Washington, Smithsonian Institution, Proceedings of the Biological Society of Washington, Volume 106, page 351