Quickness of perception or discernment; penetration of mind; the faculty of nice discrimination.
A bony, often sharp, protuberance, especially that of the ischium.
A sharp, tapering point extending from a plant.
Conscious understanding of something.
That which is detected by the five senses; not necessarily understood (imagine looking through fog, trying to understand if you see a small dog or a cat); also that which is detected within consciousness as a thought, intuition, deduction, etc.
Vision (ability)
The organisation, identification and interpretation of sensory information.
Acuity