In aristocratic circles, fluency in multiple languages and graceful dancing were regarded as important accomplishments.

accomplishments 是名词 accomplishment 的复数形式。accomplishment 由动词 accomplish（完成、实现）加上名词后缀 -ment 构成，原意是"完成的事情"，引申为"成就、才艺"。这里指需要通过学习才能掌握的技能或才能。