https://books.google.com/ngrams allows you to look at the frequency of usage of a term over time, or compare multiple terms.
Is there any similar thing for Korean words?
Korean Language Stack Exchange is a question and answer site for linguists, teachers and students of the Korean language. It only takes a minute to sign up.Sign up to join this community
I don't think there exists any service which shows you the frequency over time, though. It's also harder and more expensive to apply to the Korean language, where there are numerous particles and verb endings which obscure words' original forms. Also almost every word looked different before the major reforms of the 20th century.
Google Ngrams is a side-project of Google Books that took many years, digitizing every book page by page, by OCR and by hand(using Captchas). I don't think that would work for Korean. There just aren't enough time, money, technology, interest, and resources.