► 動詞極める  [(3)きわめる]    
meaning:  extreme  rank: 3☆ 
虐殺の
現場は
凄惨を極めた ⇨ The scene of massacre was extremely atrocious
極める  [(3)きわめる]    
meaning:  perfect  rank: 3☆ 
彼は
技を極めた ⇨ He has perfected his skills
More examples:- 株を売る時期を見極めるのは難しい ⇨ It is difficult to judge the best timing to sell the stocks