Using Clues for Unknown Vocabulary

Common Types of  Clues to the Meaning of Unknown Vocabulary

• Root words, prefixes, suffixes:  People who study birds are experts in ornithology.
•   -- The word part "-ology" means "study of."  The word part "ornith" means bird or birds.

• Similar to known words:   John's father made a sagacious comment.  (I've heard the word "sage" before, meaning a very wise person.  I will assume for now that John's father made a wise comment.  

• Grammar (Part of Speech): Many birds migrate twice each year.
• "Migrate" is being used as a verb, so it's something that the birds do.

• Contrast/Antonyms: Unlike mammals, birds incubate their eggs outside their bodies.

• Logic: Birds are always on the lookout for predators that might harm their young.
• What sort of things might harm their young?  "Predator" might mean something trying to harm something else.  I can also think of the word "prey."  Maybe a predator is the one looking for "prey,' something to kill and eat. 

• Definition: Frugivorous birds prefer eating fruit to any other kind of food.
• Wow!  It gave me the definition right in the sentence.  

• Example or illustration: Some birds like to build their nests in inconspicuous spots — high up in the tops of trees, well hidden by leaves.
• So an inconspicuous spot is one that's not easy to see. 
• Or I might know that if something is conspicuous, people will be looking at it,  so "inconspicuous"  might be the opposite of conspicuous.  
• Synonyms:  Some birds like to build their nests in inconspicuous spots, concealed spots.  

You can also use reference materials to look up the word. 
Or you could ask someone who might know. 

More examples: 

Synonyms:  His worst infraction, breaking the rules,  happened just yesterday.

Antonym: Littering is an infraction.  Instead of littering, we need to obey the rules. 

Example:  She committed an infraction at school by throwing snowballs at recess. 

Definition:  Littering is an infraction, a violation of the law. 

https://www.visualthesaurus.com/

http://www.ldonline.org/article/61511/

http://www.translationdirectory.com/article863.htm