Lagrangian point Syllabification: (La·gran·gi·an point)Pronunciation: /ləˈgranjēən, -ˈgrän-/Definition of Lagrangian point noun one of five points in the plane of orbit of one body around another (e.g., the moon around the earth) at which a small third body can remain stationary with respect to both. Lagrangian point in other Oxford dictionaries Definition of Lagrangian point in the British & World English dictionary