a person who holds moderate views, especially in politics

an unlikely alliance of radicals and moderates

make or become less extreme, intense, rigorous, or violent

I shall not moderate my criticism

the weather has moderated considerably

review (examination papers, results, or candidates) in relation to an agreed standard so as to ensure consistency of marking

the dependability of an examining system rests on those who set, moderate, and mark the papers

(in academic and ecclesiastical contexts) preside over (a deliberative body) or at (a debate)

a panel moderated by a Harvard University law professor

monitor (an internet forum or online discussion) for inappropriate or offensive content

retard (neutrons) with a moderator

the neutrons causing fission are not moderated but react at high energies