a.

1. 相等的，相同的[（+to）]
   His reply is equivalent to a refusal.

   他的回答等于是拒绝。

2. 等价的，等值的；等量的；等效的[（+to）]
   A meter is equivalent to 39.37 inches.

   一米相当于三十九点三七英寸。

3. 同意义的
4. 【化】等价的
5. 【数】等面积的，等体积的

n.[C]

1. 相等物；等价物[（+of/to）]
   A dime is the equivalent of two nickels.

   一角硬币等于两个五分镍币。

2. 同义字[（+of/for）]
   Some English words have no Chinese equivalents.

   有些英文字在中文里没有对应的词。

3. 【化】【物】当量

adj.

1. equal in value, amount, function, meaning, etc.
   ▸ (equivalent to) having the same or a similar effect as.
2. Mathematics  belonging to the same equivalence class.

n.

1. a person or thing that is equivalent to another.
2. (also equivalent weight) Chemistry  the mass of a particular substance that can combine with or displace one gram of hydrogen or eight grams of oxygen, used in expressing combining powers of elements.