Disagreeably precise or penetrating.
Savagely violent, vicious, ruthless, or cruel.
Crude or unfeeling in manner or speech.
Harsh; unrelenting.
Direct and without attempt to disguise unpleasantness.
In extreme metal, to describe the speed of the music and the density of riffs.
The natural inclination to do whatever is necessary to succeed (including extreme violence)
Used other than figuratively or idiomatically: see killer, instinct.