隐蔽人士，俗称茧居族、蛰居族，指人处于狭小空间、不出社会、不上学、不上班，自我封闭地生活。不过仍有少数隐蔽人士有出社会、运用互联网工作。日本称为“ひきこもり”或者“引き笼もり”（罗马字：Hikikomori），由“引き”（Hiki）和“笼もる”（Komoru）两部分组成，按字面解释分别为“退隐、抽离”和“隐蔽、社会退缩”。至于「茧居族」一词则是由英文cocooning翻译过来，以该英文本来形容隐蔽一族是由一位美国趋势预言家Faith Popcorn在她的1992年著作《爆米花报告》(The Popcorn Report)首先提出。

Cocooning is the name given to the trend that sees individuals socializing less and retreating into their home more. The term was coined in the 1990s by Faith Popcorn, a trend forecaster and marketing consultant:

Popcorn identified cocooning as a commercially significant trend that would lead to, among other things, stay-at-home electronic shopping. Since Popcorn coined the term, the trend has continued. The creation of the internet, home entertainment technology, advances in communication technology (cellphones, PDAs, and smartphones) which allow "work-at-home" options, and demographic changes have made cocooning an increasingly attractive option. If a reasonable amount of progress has been made when one is cocooning, one may expect the subject to have a breakthrough and emerge like a butterfly to enjoy life.