The disgruntled scientist became an unremitting critic of the entire program.

The unremitting rain ultimately ruined their dream vacation to the Bahamas.

Unremitting means something goes on and on and on without stooping

In early January, the last of a series of three operations caused an unremitting peritonitis to set in and spread, from which he died.

George's grudge against his friend was so unremittingthat they had not communicated with each other for over three years.

Also, unremitting pain that lacks an identifiable physical cause such as the majority of cases of low back pain may be considered chronic.