staple
n. countablen. a basic food or product that people use or buy all the time. It can also mean a small piece of metal used to hold papers together.
n. a main or important element of something, especially a food that forms the basis of a diet; also, a U-shaped wire fastener used to bind sheets of paper.
Rice is a staple food for millions of people.
The office manager ordered a new box of staples to keep the legal documents organized.
While wheat remains a dietary staple in the region, local farmers are increasingly diversifying their crops to protect against the economic impact of a single failed harvest.
From Middle English staple, from Anglo-Norman estaple, Old French estaple (“market, (trading) post”), from Late Latin stapula, from Frankish stapul, ultimately from Proto-Germanic stapulaz (“post”), from Proto-Indo-European *stebʰ- (“post, stem”). Compare staff. Doublet of étape and etymology 2.
From Middle English stapel (“staple, pillar, post”), from Old English stapol (“post, pillar”), from Proto-West Germanic stapul, from Proto-Germanic stapulaz, from Proto-Indo-European *stebʰ- (“post, stem”). See also Old English steppan (“to step”) and Old French estaple (“post”). Consider also stapes (“stirrup”), from Latin. Doublet of étape and etymology 1.
Often used as a noun adjunct before another noun, such as 'staple diet' or 'staple crop'.