aes·thet·ics or es·thet·ics (es-thet'iks) 
n.
1.  (used with a sing. verb) 
	a.  The branch of philosophy that deals with the nature and expression of beauty, as in the fine arts.
	b.  In Kantian philosophy, the branch of metaphysics concerned with the laws of perception.
2.  (used with a sing. verb) The study of the psychological responses to beauty and artistic experiences.
3.  (used with a sing. or pl. verb) A conception of what is artistically valid or beautiful: minimalist aesthetics.
4.  (used with a sing. or pl. verb) An artistically beautiful or pleasing appearance: “They're looking for quality construction, not aesthetics” (Ron Schram).