rationalizev. t.1. To make rational; also, to convert to rationalism.()2. To interpret in the manner of a rationalist.()3. To form a rational conception of.()4. (Alg.) To render rational; to free from radical signs or quantities.()v. i. To use, and rely on, reason in forming a theory, belief, etc., especially in matters of religion: to accord with the principles of rationalism.()Theodore . . . is justly considered the chief rationalizing doctor of antiquity. (J. H. Newman.)