The study of values and value judgments

Wiktionary Word definitions in Wiktionary
n. 1 (context uncountable philosophy English) The study of the origin, nature, functions, types, and interrelations of values; value theory. 2 (context countable English) The particular value theory of a philosopher, school of thought, etc.

WordNet Word definitions in WordNet
n. the study of values and value judgments

Wikipedia Word definitions in Wikipedia
Axiology (from Greek , axiā , "value, worth"; and , -logos ) is the philosophical study of value . It is either the collective term for ethics and aesthetics —philosophical fields that depend crucially on notions of worth—or the foundation for these fields, ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
axiology \axiology\ n. the study of values and value judgments.