improper integral
limit of a definite integral with as one or both limits approach infinity or values at which the integrand is undefined
en-GB/ɪmˈpɹɒpə ˈɪntɪɡɹəl/
en-US/ɪmˈpɹɑpɚ ˈɪnəɡɹəl/
limit of a definite integral with as one or both limits approach infinity or values at which the integrand is undefined