To evaluate the expression \( \sqrt{19} - 32 \), we first need to consider the values of each component:
- \( \sqrt{19} \) is an irrational number because 19 is not a perfect square.
- Subtracting 32 (which is a whole number and hence rational) from an irrational number results in an irrational number.
Therefore, the expression \( \sqrt{19} - 32 \) results in an irrational number.
So the correct response is: an irrational number.