The Collaborative International Dictionary of English v.0.48:
Lactifuge \Lac"ti*fuge\, n. [L. lac, lactis, milk + fugare to expel.] (Med.) A medicine to check the secretion of milk, or to dispel a supposed accumulation of milk in any part of the body. [1913 Webster]WordNet (r) 3.0 (2006):
lactifuge n 1: any agent that reduces milk secretion (as given to a woman who is not breast feeding)