vt.

1. 減少；縮小；降低
   He is trying to reduce expenses.

   他正試圖減少開支。

2. 使處於（某種狀態）；使化為，使變為[（+to）]
   The fire reduced the paintings to ashes.

   大火將這些畫作燒成了灰燼。

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

   貧窮迫使他行乞。

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

   這軍官被降為士兵。

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

   最後主席把所有的問題歸納為一個。

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

   那個癌症患者瘦得皮包骨。

9. 把……折合（成較小單位）[（+to）]
10. 【化】使還原
11. 【數】簡化，約簡
12. 【醫】使（斷骨）復位；使（脫臼）還臼

vi.

1. 減少；縮小；降低
2. 減輕體重，減肥
   It is easy to reduce if you watch your diet.

   你如果注意飲食，減肥並不難。

3. 歸納為，化為[（+to）]
4. 換算；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).