The particle-physics term hadron refers to a
subatomic particle that consists of two or more quarks,
such as a baryon (consisting of an odd number of quarks,
such as a proton or neutron, that have three each),
or a meson (which has an even number of quarks).
Hadrons are held together by the strong force,
the force carried by gluons.
One prominent use of the term hadron is in the name Large Hadron Collider (LHC),
which accelerates protons.
The term hadronic matter is sometimes used, basically
a synonym for baryonic matter, i.e., consisting (largely)
of protons and neutrons.