elegance n.

late 15c., "tastefully ornate," from Old French élégant (15c.) and directly from Latin elegantem (nominative elegans) "choice, fine, tasteful," collateral form of present participle of eligere "select with care, choose" (see election). Meaning "characterized by refined grace" is from 1520s. Latin elegans originally was a term of reproach, "dainty, fastidious;" the notion of "tastefully refined" emerged in classical Latin. Related: Elegantly.

Elegant implies that anything of an artificial character to which it is applied is the result of training and cultivation through the study of models or ideals of grace; graceful implies less of consciousness, and suggests often a natural gift. A rustic, uneducated girl may be naturally graceful, but not elegant. [Century Dictionary]

1690s, from French inélégance (16c.) or directly from Late Latin inelegantia, from in- "not, opposite of" (see in- (1)) + Latin elegantia "taste, propriety, refinement" (see elegance).