An end to reason? (4)

I believe the answer is:

able

(Other definitions for able that I've seen before include "Of high proficiency" , "Competent as, say, sailor" , "Having considerable skill" , "Gifted" , "showing talent" .)

I've seen this clue in the LA Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.