A "dull ache" refers to a constant, mild pain that is not sharp or intense. It is often described as a persistent discomfort or throbbing sensation. Full definition
Indigestion, dull ache in stomach accompanied by lots of burping, post PHD. (perfecthealthdiet.com)
Beyond dulling the ache of a screaming infant and sleepless nights, drinking beer might actually be beneficial for my wife's newest job: breastfeeding. (bonappetit.com)
Whether it takes the form of a constant dull ache or sharp, shooting pains, chronic back pain can interfere with your ability to lead a normal life. (chicagolawyer.com)