Sense file
How the sense moved
The archive follows the dated record first, then reads the social or rhetorical pressure that hardened, softened, narrowed, or reversed the word.
Older meaning
A final boundary, with one famous Civil War prison use for a line prisoners could be shot for crossing.
Modern meaning
The latest time by which something must be completed.
Research lens
A good caution entry because the dramatic origin story is memorable but too simple if told as the whole modern path.
Meaning trail
Older use
dead line
A severe boundary sense existed before the office metaphor.
Bridge
absolute final limit
Industrial and newspaper uses tightened the timing idea.
Now
due date
The violence faded into scheduling pressure.