Entry 1 sense Webster, 1913 Celeriac · Ce·le·ri·ac · IPA /səˈlɛəɹiæk/ 01 n. Turnip-rooted celery, a from of celery with a large globular root, which is used for food. 1. Turnip-rooted celery, a from of celery with a large globular root, which is used for food.(Bot.)