pret·tyˈpridē/

adjective
1. attractive in a delicate way without being truly beautiful or handsome.

adverbinformal 

2. to a moderately high degree; fairly.

noun informal

3. an attractive thing, typically a pleasing but unnecessary accessory.

verb

4. make pretty or attractive.

adjective

5. pleasing or attractive to the eye, as by delicacy or gracefulness:

PRETTY: Noun

Something to cause your heart to flutter, to cause your face to flush. Something to compete with beautiful, with handsome, but not leaning on the crudeness of "hot" or "sexy". Simplistic and pleasing, sweet and perfect. Someone to wish for on the desolate nights, if only for their prettiness to cure the ache of mind and soul. 

"She was prettier than the bluest star in the sky."