Archaic KJV Word
Transgression
Modern equivalent: sin
What Was Lost
The distinction between transgression (deliberate covenant rebellion), sin (missing the mark), and iniquity (twisted nature). Hebrew distinguished pesha (transgression), chata (sin), and avon (iniquity) as three different conditions. English collapsed them all into 'sin.'
Closest Survivor in Modern English
transgression (still used but hollowed to mean 'breaking a rule')
Peak Usage (1611)
KJV Psalm 32:1 -- 'Blessed is he whose transgression is forgiven'
Died ~1970
Weakened from 'covenant-breaking rebellion' to 'rule violation,' losing the relational betrayal dimension as covenant theology faded from public discourse.
What Replaced It
“sin”
Undifferentiated; transgression was a specific category of sin -- deliberate rebellion, not mere weakness
“violation”
Legal and impersonal; transgression implied personal betrayal of a covenant relationship
“wrongdoing”
Mild and vague; transgression carried the gravity of treason