the.com/inhibitor

means A substance that slows or blocks a chemical reaction or biological process, often by jamming itself into the spot an enzyme needs to work.

from From Latin 'inhibere' — 'in-' (on, into) plus 'habere' (to have, to hold) — meaning to hold in or restrain. The same root gives us 'inhibit' and 'inhibition.' Latin speakers used it for reining in horses or holding back actions; chemists and biologists later borrowed the word for molecules that rein in reactions the same way, holding enzymes back from doing their work.