substitute, change, convert, replace, period, age, counter for decades of ages, eras, etc., generation, charge, rate, fee
代 centers on one thing standing in for another: substituting, replacing, or taking a turn. This extends naturally to a span of time (an era or generation) and to a fee or charge as something given in exchange.
代 combines 亻 (person) with 弋, which likely contributed the sound. The idea of a person standing in for another gives the core meaning of substitution.
A person 亻 holding a stake 弋 marks a spot where someone else will take over. Picture a relay runner passing a stake to the next runner: one person replaces another.
For ダイ, imagine a substitute runner named Dai who takes the stake and runs the next leg: Dai -> ダイ.
period; epoch; era; age
representation; representative; delegate; delegation
substitute; replacement; substituting; replacing
present age; present day; today
generation
age; era; period; date
representation; agency; proxy
ancient times; distant past; antiquity
change; alternation; rotation; replacement; substitution; shift; relief; taking turns
first generation; founder
acting as agent; acting on (someone's) behalf; executing business for
present day; modern times; recent times
substitution
successive generations; successive emperors
metabolism
price; cost; charge; payment; bill; fee
proxy; agent; substitute; deputy; alternate; representative; attorney
compensation; reparation; indemnification
substitution
pinch-hitting; pinch hitter
for generations; from generation to generation; generation after generation; through the ages
pronoun
previous generation (of a family); previous head of the family; one's (late) father
thousand years; thousand generations; thousand ages; eternity
substitute (actor); stand-in; fill-in; understudy; double
speaking by proxy; speaking for (someone else); acting as spokesman (for); representing (the views, feelings, etc. of)
unheard-of; unprecedented; unparalleled in history (unparallelled); record-breaking
substitution (for someone else); substitute; stand-in; scapegoat; sacrifice
very long period; forever
Imperial reign
renewal; replacement; regeneration; rejuvenation
parliamentarian; member of a congress
taking over (another's debt, work); shouldering someone else's burden; subrogation
local governor (Edo period); local magistrate; bailiff
the next era
permanence; eternity
generation; lifetime; age
representing others in a conference
old-fashioned; antiquated; anachronistic
the teens (10-19); teenage
another helping; second helping; seconds; refill
three generations; three periods
alternately; by turns
substitute; deputy; proxy; representative; agent
agency; agent
nth generation; nth (person to occupy a position, e.g. president)
most important work (of a writer, artist, etc.); representative work; masterpiece; magnum opus; major work
representative; exemplary; model
the 1900s
same age; same period
student days
historical play; period drama
anachronism
Edo period (1603-1868)
modern; modernistic
modern society
ransom demand
modern
modern poetry; modern-style poetry
golden age