No, -10 is not an irrational number, it is a rational number. If we consider the sign, it is a negative type of rational number. As per the description of the answer we can elaborate the definition of the Irrational Numbers and by the help of the definition of the irrational numbers we can confirm that all the numbers like -10 are not irrational numbers but types of Rational Numbers.

Let us go through the definition of the irrational number that is any number we cannot express in the form of some Ratio like p/q is called as the irrational number. We cannot easily write any irrational number in to some fractional form. It is a type of real number that can never be expressed in the form of ratio of two non-zero numbers. Now, the number we have here is -10, and as per the form of the irrational number to this number, we can observe here that we can easily give the form of the rational number to this number (-10). In the form of the rational number we know that any number that can be expressed in the form of some ratio like a/b such that the denominator number is not equals to the number zero, so we can write the number -10 as in the form -10/1, and comparing this form with rational number form (p /q), we can now say that here p = -10, and q = 1. So the number -10 can be written in the form of rational number and that why it is the rational number and not an irrational number.

So, the answer to the question ‘is -10 an irrational number’ can be easily stated as 'No'.