积弱

cumulative weakness / to decline (over time) / degeneration

weak / feeble / young / inferior / (following a decimal or fraction) slightly less than

weak; feeble / young / inferior; not as good as / (following a decimal or fraction) slightly less than

to amass / to accumulate / to store / measured quantity (such as area of volume) / product (the result of multiplication) / to integrate (math.) / to solve (or integrate) an ordinary differential equation (math.) / old / long-standing