extension, increase and expansion
denotation, connotation and application
comprehension, understanding and knowing
polysemy, homograph and homophone
同义词的区别包括:(1) 外延上的区别 (Difference in denotation)、(2) 内涵上的区别 ( Difference in connotation)、(3) 应用上的区别 (Difference in application)