אָכֵן (ʾākēn) is
a Hebrew adverb
meaning firmly. It appears
18 times
in 9 books of the Hebrew Bible
(Strong's H403).
Also rendered
surely
Same Hebrew root (TWOT 86)
Range of meaning (TWOT 86)surely, truly; but indeed; firmly; but; certainly, nevertheless, verily
Full entry: Brown-Driver-Briggs and Strong's
אָכֵןadverb
a.surely, truly
b.emphasizing a contrast, but indeed
Strong's H403אָכֵן: firmly; figuratively, surely; also (adversative) but KJV:but, certainly, nevertheless, surely, truly, verily.
Meanings: Brown-Driver-Briggs (1906) and Strong's Hebrew Dictionary (1890), public domain, via the Open Scriptures Hebrew Bible Project (CC BY 4.0). TWOT numbers for reference only.