1. CORRODE (VERB): waste

Synonyms: erode, deteriorate     Antonyms: build, construct

Example Sentence:

 Engineers found that the structure had been corroded by moisture.

2. CORROSIVE (ADJECTIVE): acerbic

Synonyms: caustic, vitriolic        Antonyms: gentle, nice

Example Sentence:

Sodium and Sulphur are highly corrosive elements.

3. COUNTERMAND (VERB): cancel a command

Synonyms: reverse, override            Antonyms: allow, approve

Example Sentence:

I can’t countermand her orders.

4. CONVOLUTED(VERB): complicated

Synonyms: intricate, tangled        Antonyms: direct, simple

Example Sentence:

It is hard to solve the question because a convoluted reasoning is applied in it.

5. COWER(VERB): to draw back and crouch in fear

Synonyms: cringe, crouch     Antonyms:  face, meet

Example Sentence:

He was cowering away from the fierce dog. 

6. COY(ADJECTIVE): very modest

Synonyms: bashful, evasive    Antonyms: immodest, unshy

                        

Example Sentence:

She gave her brother’s friend a coy smile.

7. CRAMP (NOUN):stiffness

Synonyms: pain, ache              Antonyms: comfort, ease

Example Sentence: 

She started getting stomach cramps this morning.

8. CRASS (ADJECTIVE):not intelligent; irresponsible

Synonyms: stupid, gross       Antonyms: sharp, smart

Example Sentence:

 They have behaved with crass insensitivity.

9. CREDENCE (NOUN):acceptance or belief

Synonyms: trust, assurance    Antonyms:  denial, disbelief

Example Sentence:

 I cannot give credence to his account.

10. CREED(NOUN): belief

Synonyms: principles, doctrine     Antonyms: disbelief, doubt

Example Sentence:

The centre is open to all, no matter what race or creed.