Back In September a post was written at the Oxford English Dictionary's website titled "The OED gets a K-update," one which gives some history of the word 'Korea' in the English language and lists the 26 words of Korean origin newly-added to the OED.
One word is "Konglish, n. and adj.", which as the OED dates as a noun to 1970 and as an adjective to 1975. Another word is "fighting, int.", which the OED dates to the 2000s. As the dates in this article I wrote awhile back reveal, these dates are incorrect. "Konglish" may have first appeared in English in 1967, but in Korean its likely first appearance in was in two articles in the Kyonghyang Shinmun in July 1962 (here and here, where it is cutely defined as "코리언(韓語)과 잉글리쉬(英語)의 비빔밥이란 말이죠" - "a bibimbap of Korean and English").
As for the first appearance of "fighting," it predates the OED's guess by at least 30 years (and perhaps quite a bit longer, if we look at these results). The first mention in English of 'fighting' that I found was in this October 21, 1975 Korea Times article, and recently I found this article in the February 27, 1972 issue of 주간여성 (Weekly Woman), about a young woman aiming to be a pilot:
I would tend to think the operative 'first appearance' of the words in these cases should be the versions in Hangeul, since they are English-derived words (or combinations of words) to begin with.
(And yes, I did suggest these edits to the OED shortly after these new additions were made public; perhaps corrections will be made at some point.)