Archaic KJV Word
Fine
Modern equivalent: pure
What Was Lost
The furnace behind the word. Fine gold was not merely good gold but gold that had passed through fire, had its impurities burned away, and emerged as nothing but pure metal. When Revelation describes Christ's feet as fine brass, it means brass refined in the furnace until it blazes -- not brass that is 'okay.'
Closest Survivor in Modern English
refinery (the place where things are made fine -- preserves the purification meaning)
Peak Usage (1611)
KJV Proverbs 25:12 -- 'An ornament of fine gold'; Revelation 1:15 -- 'His feet like unto fine brass'
Died still used but diluted (~1900)
Expanded from 'pure/refined/of highest quality through purification' to the vague approval 'okay/satisfactory' ('I'm fine'), draining a word of exacting purity into casual adequacy.
What Replaced It
“pure”
Chemical; fine-as-pure meant purified through fire, tested and proven -- not merely uncontaminated
“refined”
Process-focused; fine emphasized the result -- the gleaming, perfected end product
“okay”
The modern default meaning -- complete evacuation of all quality, purity, and excellence