settle (debt, etc.), relieve (burden), finish, come to an end, excusable, need not
済 centers on bringing something to a satisfactory close: settling a debt, finishing a task, or relieving a burden. The sense of being excusable or not needing to do something extends from the idea that the matter is already resolved.
済 combines 氵 (water) with 斉, which likely contributes the sound and the idea of evenness or leveling. The original sense may have been crossing a river, from which the ideas of finishing and settling developed.
Water 氵 flows evenly 斉, like a river crossing that brings you to the other side. When you cross, the journey is finished and debts are settled.
For サイ, imagine a sigh of relief when a debt is finally settled: sigh -> サイ, and the water washes the burden away.
economy; economics
excuse me; pardon me; I'm sorry; I beg your pardon
to finish; to end; to be completed; to be resolved
relief; aid; help; rescue
settlement (of an account); liquidation of debts; payment
repayment; reimbursement; refund; redemption
to finish; to get it over with; to conclude
inexcusable; unjustifiable; unpardonable
to finish; to make an end of; to get through with; to let end
mutual aid
repayment; settlement (of a debt); paying off; reimbursement (of expenses)
used (ticket, stamp, etc.); spent (fuel, battery, etc.)
Japanese economy
payment method
Economic Planning Agency (1955-2001)
economics
economic blockade; embargo
rate of economic growth
economic world; financial circles; business community
economic; financial
economic research institute
free economy