v (使)减小(少，弱)，(使)降低((cause to) become less in size， number， amount， strength or quantity) [I， T+n]：The percentage of old workers/Interest in sports is～ing. 老工人的比率/对运动的兴趣在降低。The swelling/cold has～d. 消肿了/寒冷减弱了。Student numbers have～d by 1000/10 percent. 学生人数减少了1000/10%。Profits have～d over last year. 利润比去年减少了。Our sales/Water consumption/The supply of food～d last summer. 去年夏天我们的销售量/耗水量/食品供应减少了。～sb's wages/the cost of production/the temperature in the room 降低某人的工资/生产成本/室内温度;～the dose of medicine/the swelling/the speed 减小药的剂量/消肿/减慢速度;(university)～the number of students(大学)减少学生人数;(government)～imports(政府)减少进口;〖同〗lessen， reduce;〖反〗increase，enlarge;

n(1) 减小(少，弱)，降低(act or process of decreasing; reduction) [U] [N(in)]： some～in the crime rate犯罪率一定程度的降低;〖同〗lessening， reduction;〖反〗growth， increase;

(2) 减少之量(amount by which sth decreases) [C][N(in/of)]：There has been a (gradual/big)～in the number of boys/population/sales/imports. 男孩数/人口/销售量/进口额(逐渐/大大)减少了。There has been a(20%)～in production/unemployment. 生产/失业减少了(20%)。There was a～of heat. 炎热程度降低了。a～of 30 percent/of over 1000减少30%/1000多;〖反〗increase;

on the decrease 在减少：The demand for tea/crime is on the～. 茶的需求/犯罪在减少。

【辨异】decrease与reduce和shrink都可表示数量变少(小)。decrease指尺寸、体积、数量上逐渐地、持续地减少(小)，常常是因为某种不可觉察的原因或固有的过程，如：The swelling～d daily.(肿胀一天天地消下去。) reduce(使减少(小)，使降低)指人为的减少(小)，一般只用作vt，如： reduce the weight of sth(减少……的重量);shrink(缩小，收缩)指由于固有特性在特有的条件下缩小，如：Many fabrics shrink in hot water.(许多织物在热水中收缩。) 还有diminish((使)减小，(使)显得小)通常指外部原因造成的不断减少，如：Evaporation caused the water in the pool to diminish.(蒸发使池塘里的水减少。)