acheacheachesachedaching2noun (no plural)a pain that lasts for a long time: If you eat all those sweets, you'll get stomach ache.She's got earache.grammarWe often use ache with a part of the body. In British English, we usually use ache without ‘a’ or ‘an’: • I've got backache. But we always say ‘a headache’: • I've got a terrible headache. In American English, we usually use ache with ‘a’ or ‘an’, especially when talking about a particular attack of pain: • I have an awful toothache.acheacheachesachedaching1verb (aches, aching, ached)to hurt; to give you pain: She was aching all over.My legs ached after the long walk.