|Main Entry:||hygiene hypothesis|
|Part of Speech:||n|
|Definition:||a theory that children not exposed to bacteria and dirt develop weak immune systems and are prone to adult allergies, asthma, etc.|
|Example:||The hygiene hypothesis was developed to explain the observation that hay fever and eczema, both allergic diseases, were less common in children from larger families, which were presumably exposed to more infectious agents through their siblings.|
Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.