Archaic KJV Word
Manna
Modern equivalent: unexpected blessing
What Was Lost
The daily discipline. Manna could not be hoarded -- it rotted overnight (except before Sabbath). God was training Israel to depend on Him one day at a time. 'Give us this day our daily bread' directly echoed manna. The entire theology of daily dependence, anti-hoarding, and trust-for-tomorrow was embedded in this one word.
Closest Survivor in Modern English
manna (still used metaphorically -- 'manna from heaven' -- but the daily-discipline theology is gone)
Peak Usage (1611)
KJV Exodus 16:15 -- 'They said one to another, It is manna: for they wist not what it was'; John 6:31 -- 'Our fathers did eat manna in the desert'
Died still used but trivialized (~1900)
Hebrew man hu ('what is it?') was the name born of bewilderment -- food appearing from nowhere. Reduced to a metaphor for 'unexpected good fortune' or forgotten entirely. The daily-dependence theology was lost.
What Replaced It
“miracle food”
Supernatural only; manna was specifically daily, just-enough provision teaching moment-by-moment dependence
“windfall”
Lucky bonus; manna came with strict rules -- take only today's portion, nothing extra
“provision”
Generic supply; manna was specifically enough-for-today, teaching trust for tomorrow