After the deduction of fees, the net profit was lower than expected.

deduction 是名词，来自动词 deduct（扣除、减去），deduct 由前缀 de-（表示"向下、去除"）和词根 duct（引导、带领）组成，字面意思是"向下引导"，引申为"扣除"。 deduction 指"扣除、减去"的动作或结果，在财务中特指从总收入中减去费用或成本。