rə̇ˈgresiv, rēˈ-, -sēv also -səv adjective
1. : that regresses or tends to regress : retrogressive
2. : characterized by or derived from reasoning backward (as from effect to cause or from observed facts to a principle)
3. : constituting or relating to a technique of micrological staining in which the stain is applied to excess and the excess later removed in order to enhance the specificity of the staining
4.
a. : of, relating to, typical of, or tending to produce regression
regressive tissue changes
b. : being, characterized by, or developing in the course of an evolutionary process involving increasing simplification of bodily structure
5. : having the nature of the first of two sounds dependent on the nature of the second
regressive assimilation
6. : decreasing in rate as the base increases — used of taxation and methods of apportioning taxes
7. : degressive b
• re·gres·sive·ly -sə̇vlē, -li adverb
• re·gres·sive·ness -sivnə̇s, -sēv- also -səv- noun -es