What does "fundamental constant" mean?

any of a set of physical quantities that play a fundamental role in basic theories

Fundamental constant

Common synonyms include: base, basic constant, central, constant of nature, crucial, defining constant.

noun

noun ·Rare ·Advanced level

Noun

1
any of a set of physical quantities that play a fundamental role in basic theories
2
A physical quantity that is not a function of other constants, such as Π (pi), C (light speed), etc. The smallest common denominators of physics, and the parameters or dimensions for the 'position' of our universe in the multiverse.