acumen

noun3

1. •
   Quickness of perception or discernment; penetration of mind; the faculty of nice discrimination; acuity of mind.

   • "I am going to ask you a question that does not require much legal acumen to answer," said Lord Meersbrook to his attorney, when he called the next day in Lincoln's Inn;... — 1842
2. •
   A sharp, tapering point extending from a plant.

   • 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
3. •
   A bony, often sharp, protuberance, especially that of the ischium.

   • DIAGNOSIS—Rostrum usually with marginal spines, tubercles, or angles at base of acumen, and rarely with low medina carina. — 1981