- A combining form prefix signifying first, primary,
primordial; as, protomartyr, the first martyr; protomorphic, primitive
in form; protoplast, a primordial organism; prototype, protozoan. - Denoting the first or lowest of a series, or the one having
the smallest amount of the element to the name of which it is prefixed;
as protoxide, protochloride, etc. - Sometimes used as equivalent to mono-, as indicating that the
compound has but one atom of the element to the name of which it is
prefixed. Also used adjectively.
Definition
