Dull discomfort is a term used to describe a type of pain that is not sharp or intense, but rather a dull, persistent ACHE. The term can be broken down into two crossword solutions: ACHE (4 letters) and ACHES (5 letters). ACHE is a noun that describes a dull, continuous pain, while ACHES is the plural form of the same word. Both words are used to describe a type of pain that is not sharp or intense, but rather a dull, persistent ACHE.