这个单词没有前缀,如果是unsatisfactory,那么un是前缀.
后缀-ory,一般是形容词后缀.
这个单词的词根,请阅读
satisfy
early 15c.,from M.Fr.satisfier,from O.Fr.satisfaire,from L.satisfacere "discharge fully,comply with,make amends," lit."do enough," from satis "enough" (from PIE base *sa- "to satisfy;" see sad) + facere "perform" (see factitious).