delayed effect; delayed action
Used for effects that appear after a delay, such as medication, policy, or mechanical action. Often contrasted with 速効 (immediate effect).
See also: 速効
This medicine is slow-acting, so it won't take effect right away.
Using slow-release fertilizer keeps the effect lasting longer.
即効 describes an effect that appears right away, while 遅効 describes one that takes time to appear.
slow-acting fertilizer
Compound of 遅 (chi, 'late, delayed') and 効 (kō, 'effect, efficacy'). The reading ちこう is the standard on'yomi combination.