synonym n. 同义词 

synonymy n. 同义词研究；同义词汇编

synthesis [syn- = together 共；thesis = putting 放置=>“putting together 共置一处” n. the combination of parts into a whole 综合；综合物 / I cannot believe that they can achieve a synthesis between dictatorship and anarchism. 我不相信他们能将独裁政治与无政府主义合成一体。

synthesize v. 综合；合成 

synthetic a. 综合的；合成的；人造的

下面举例说明syn-的异体的构词规律。

syllable [ syl- (syn-) = together 共；lable = to take 取=>“letters taken together 收取在一块的字母”→]n . a word or part of a word spoken as a unit 音节 / The word vocabulary has five syllables. Vocabulary这个词有五个音节。

syllabary n. 音节表；（日语）五十音图 

syllabic a. 音节的；自成音节的

symbol [ sym- ( syn-) = with 与；bol = to throw 投“sth. thrown out with sth. else 与它物共同投放出来之物”→]n. sth. that stands for sth. else 象征，象征物 / The olive branch is the symbol of peace. 橄榄枝是和平的象征。

symbolic a. 象征的；象征性的；符号的 

symbolize v. 把…作为象征；代表 

symbolism n. 象征主义；象征手法

sympathy [ sym- ( syn-) = with 与；pathy = feeling 感情=>“a feeling with or for sb. else 与他人共有的感情 ”→]n. a sharing of another's sorrow or trouble; fellow feeling 同情；同情心 / A good doctor knows that sympathy is just as important as medicine. 好医生懂得同情心跟药物一样重要。