building block

American  

noun

1. block.

2. one of a set of cube-shaped blocks used by children to make simple constructions.

3. a basic element or component.

   the building blocks of proteins.

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building block British  

noun

1. a block of stone or other material, larger than a brick, used in building

2. a component that fits with others to form a whole

   standardized software building blocks

3. another name for (the child's toy) block

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Etymology

Origin of building block

First recorded in 1840–50

Example Sentences

It will be a building block and a key ingredient in every new “unicorn” — a company with a valuation of at least $1 billion.

From MarketWatch • Apr. 21, 2026

That causes the molecule to crack into hydrogen and ethylene, the basic building block of plastics such as polyethylene.

From The Wall Street Journal • Apr. 5, 2026

Speaking to TNT Sports, returning captain John McGinn suggested that the result had provided Villa with a "building block" and the opportunity to "reset" after a difficult few weeks.

From BBC • Mar. 12, 2026

In test tube studies, bone forming cells quickly moved into the structured hydrogel and began producing collagen, a key building block of bone.

From Science Daily • Mar. 3, 2026

It would be lovely to cuddle up beside her while Georgie sat nearby, building block towers and pretending not to listen.

From "The Old Willis Place" by Mary Downing Hahn

Related Words

• constituent
• ingredient