His dishonesty during the exam resulted in expulsion from school.

dishonesty 是由前缀 dis-（表示"否定、相反"）和名词 honesty（诚实）组成的复合名词。honesty 来自形容词 honest（诚实的）加上名词后缀 -ty。 dishonesty 的字面意思是"不诚实"，指故意欺骗或说谎的行为。