rickets

noun

rick·​ets ˈri-kəts How to pronounce rickets (audio)
plural in form but singular in construction
: a deficiency disease that affects the young during the period of skeletal growth, is characterized especially by soft and deformed bones, and is caused by failure to assimilate and use calcium and phosphorus normally due to inadequate sunlight or vitamin D

Word History

Etymology

origin unknown

First Known Use

1634, in the meaning defined above

Time Traveler
The first known use of rickets was in 1634

Browse Nearby Words

Cite this Entry

“Rickets.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rickets. Accessed 10 Sep. 2025.

Kids Definition

rickets

noun
rick·​ets ˈrik-əts How to pronounce rickets (audio)
: a disease of young people and animals in which the bones are soft and deformed due to an inability of the body to use calcium and phosphorus because of a lack of vitamin D

Medical Definition

rickets

noun, plural in form but singular in construction
rick·​ets ˈrik-əts How to pronounce rickets (audio)
: a deficiency disease that affects the young during the period of skeletal growth, is characterized especially by soft and deformed bones, and is caused by failure to assimilate and use calcium and phosphorus normally due to inadequate sunlight or vitamin D

called also rachitis

see osteomalacia

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