sentence1: while antonymy is defined as the oppositeness between words , synonymy refers to words that are similar in meaning ( cite-p-21-1-2 , cite-p-21-4-5 ) .
sentence2: while antonymy is defined as the oppositeness between words , synonymy refers to words that are similar in meaning ( cite-p-11-1-2 , cite-p-11-1-10 ) .