실증이 · 실증을
empirical proof, demonstration by evidence
Example
그 가설은 아직 실증 연구로 확인되지 않았습니다.
That hypothesis has not yet been confirmed by empirical research.
Word parts
실 real, actual+증 proof
Literally 'proof by actual facts'.
Good to know
Don't confuse with 싫증 'boredom, weariness' — they sound alike: [실쯩].