vt.

1. 减少；缩小；降低
   He is trying to reduce expenses.

   他正试图减少开支。

2. 使处于（某种状态）；使化为，使变为[（+to）]
   The fire reduced the paintings to ashes.

   大火将这些画作烧成了灰烬。

3. 迫使[H][（+to）]
   Poverty reduced him to begging.

   贫穷迫使他行乞。

4. 降服，攻陷
5. 使降级，使降职[（+to）]
   The officer was reduced to the ranks.

   这军官被降为士兵。

6. 把……归纳，把……归并[（+to）]
   Finally the chair reduced all the questions to one.

   最后主席把所有的问题归纳为一个。

7. 把……弄碎；把……分解；把……分析[（+to）]
8. 使变弱，使变瘦[H][（+to）]
   The cancer victim was reduced to skin and bones.

   那个癌症患者瘦得皮包骨。

9. 把……折合（成较小单位）[（+to）]
10. 【化】使还原
11. 【数】简化，约简
12. 【医】使（断骨）复位；使（脱臼）还臼

vi.

1. 减少；缩小；降低
2. 减轻体重，减肥
   It is easy to reduce if you watch your diet.

   你如果注意饮食，减肥并不难。

3. 归纳为，化为[（+to）]
4. 换算；折合

v.

1. make or become smaller or less in amount, degree, or size.
   ▸boil (a sauce or other liquid) so that it becomes thicker and more concentrated.
   ▸chiefly N. Amer. (of a person) lose weight.
   ▸Photography  make (a negative or print) less dense.
2. (reduce someone/thing to) bring someone or something by force or necessity to (an undesirable state or action).
   ▸ (reduce someone to) make someone helpless with (shock, anguish, or amusement).
3. (reduce something to) change something to (a simpler or more basic form).
   ▸convert a fraction to (the form with the lowest terms).
4. Chemistry  cause to combine chemically with hydrogen.
   ▸undergo or cause to undergo a reaction in which electrons are gained from another substance or molecule. The opposite of oxidize.
5. restore (a dislocated body part) to its proper position.
6. archaic besiege and capture (a town or fortress).