📘 English Definition（英文释义）
- 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.