Archaic KJV Word
Vine
Modern equivalent: plant
What Was Lost
The Israel identity. Isaiah 5 described Israel as God's vineyard -- planted, tended, protected, and expected to produce justice and righteousness. When Jesus said 'I am the true vine,' He was making a staggering claim: He was the true Israel, the faithful vine where the nation had been unfaithful. Branches in Him were the renewed people of God.
Closest Survivor in Modern English
vine (still used in John 15 teaching but the Israel/covenant-community dimension is usually missed)
Peak Usage (1611)
KJV Isaiah 5:1-7 -- 'My wellbeloved hath a vineyard'; John 15:5 -- 'I am the vine, ye are the branches'
Died still used but de-covenanted (~1800)
Hebrew gephen ('vine/the symbol of Israel as God's cultivated people/the covenant community God planted, tended, and expected fruit from') reduced to 'a plant that makes grapes.'
What Replaced It
“grapevine”
Agricultural; the vine was Israel's national symbol -- God's planted, tended, beloved people
“plant”
Generic; the vine carried an entire narrative of planting, tending, disappointing fruit, and restoration
“connection”
Abstract; when Jesus said 'I am the vine,' He was claiming to be the true Israel