よろしい
よろしい · yoroshii · JLPT N4 · i-adj
OK
Polite upgrade of よい (good): yoi + roshi = yoroshii
Same word inside よろしく (yoroshiku), the greeting you already know. よろしく is literally the adverb form: treat me well. So yoroshii = the formal good, used in よろしいですか (is that all right?).