Anti and onym

ANTONYMS
The term antonymy in semantics derives from the Greek words anti and onym, which mean opposite and name. The opposite of antonymy is synonymy.
Antonymy in semantics refers to words that have opposite meanings. These are usually in pairs, for example: hot/cold, tall/short, loud/quiet. Antonymy can be found across all parts of speech.

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  Adjective: easy/hard, wet/dry, hot/cold
  
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  Nouns: hero/villain, freedom/slavery
  
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  Verbs: answer/ask, discourage/encourage
  
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  Adverbs: now/then, loudly/softly
  
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  Propositions: on/off, above/below
  

Antonymy can also be found in idioms:

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  Although they are twins, their personalities are night and day.
  
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  Things don't always go as you want. You have to learn to take the bad with the good.
  

There are three types of antonym which are categorized by the relationship between the opposing words.
Gradable antonyms Hot and cold are gradable antonyms. Gradable antonyms define words that are at the opposite ends of a spectrum with some gradation between the two extremes. In our temperature example we have hot - cold, with warm between hot and cold. Other examples include empty - full (gradations: half empty or half full), high - low (gradation: medium), and young - old (gradation: teenager).
Complementary antonyms explain an either-or relationship between the opposite word pairs.Remember when you have to answer true or false questions on tests? This is an example of a complementary antonym. There are only two options, either true or false. There is no half-true or half-false. Because of this, each complementary antonym can exist independently of the other and is usually its absolute opposite. Other examples are dead/alive, exterior/interior, and yes/no.
Relational/converse antonyms
Relational/converse antonyms show a dependent relationship between opposite words. A word from the pair can't exist without the other. For example, open/close. A shop owner must first open the shop before they can close it. Other examples include husband/wife, front/back, and doctor/patient.