Past tense of 'ail,' meaning to cause pain, trouble, or suffering to someone, or to be the matter with someone.
From Old English 'eglan' meaning 'to plague or torment.' The -ed suffix marks past tense. The meaning has remained remarkably stable for over a thousand years.
The phrase 'What ails you?' sounds old-fashioned now, but it was the go-to question for centuries—doctors and healers would ask this to understand someone's symptoms!
Complete word intelligence in one call. Free tier — 50 lookups/day.