The faculty of precise discernment or perception; sensitiveness
Shrewdness, quickness of mind
Violence of a disease, which brings it speedily to a crisis.
The quality of being acute or pointed
Shrillness; high pitch; – said of sounds.
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