One of the individual entities contributing to a whole
TMA-2 is the basic building block from which most modern amphetamines were originally derived.
The tire bale is a building block made from compressed tires.
beta carotene is a building block of vitamin A, which is essential for human health.
If the surface is too sticky the component building block molecules won't circulate and find their complementary bonding partners to make the honeycomb.
The building block approach is used to account for the effect of foundations on systems designed to provide vibration isolation.