The paper analyzes the nature and potential applications of contextual definitions in modern philosophy of language and jurisprudence. It is shown that the distinction between a contextual definition and a genus–differentia definition proposed by some legal philosophers, where the latter is considered ineffective and unproductive in analyzing legal concepts, is sometimes deceptive. The weaknesses of the argument about this distinction are shown by examining the constitutional legal rules, which can be considered an example of the application of contextual definitions in legal science. On the basis of this claim, it is shown that these two types of definition may well coexist at least in legal language and in some sense complement each other, when the different areas of their applicability are taken into account.