lactealPronunciation: /ˈlaktɪəl/Definition of lacteal adjective of milk. Anatomy (of a vessel) conveying chyle or other milky fluid. noun (lacteals) Anatomy the lymphatic vessels of the small intestine which absorb digested fats. Origin: mid 17th century: from Latin lacteus (from lac, lact- 'milk') + -allacteal in other Oxford dictionaries Definition of lacteal in the US English dictionary