- Protofibril Subst. Adj.
- Protogalaxy Subst. Adj.
- Protogynous Adj.
- Protogyny Subst.
- Protohaematin Subst. Adj.
- Protohematin Subst. Adj.
- Protoheme Subst. Adj.
- Protohippus Subst. Eigenn.
- Protohistorian Subst.
- Protohistoric Adj.
- Protohistory Subst.
- Protohuman Adj. Subst.
- Protolanguage Subst. Adj.
- Protolithic Adj.
- Protolysate Subst. Adj.
- Protolysis Subst. Adj.
- Protolytic Adj.
- Protomorphic Adj.
- Proton Subst. Adj.
- Protonate Verb
- Protonated Adj. Part. Perf.
- Protonation Subst. Adj.
- Protonema Subst. Adj.
- Protonic Adj.
- Protonophore Subst. Adj.
- Protooncogene Subst. Adj.
- Protopathic Adj.
- Protopectin Subst. Adj.
- Protopectinase Subst. Adj.
- Protophloem Subst. Adj.
- Protophyte Subst.
- Protoplanet Subst. Adj.
- Protoplanetary Adj.
- Protoplasm Subst. Adj.
- Protoplasmal Adj.
- Protoplasmatic Adj.
- Protoplasmic Adj.
- Protoplasmolysis Subst.
- Protoplast Subst.
- Protoplastic Adj. Subst.
- Protopodite Subst. Adj.
- Protopope Subst.
- Protoporphyria Subst.
- Protoporphyrin Subst. Adj.
- Protopresbyter Subst.
- Protostar Subst.
- Protostele Subst. Adj.
- Protostellar Adj.
- Prototherian Adj. Subst.
- Protothetics Subst.
- Prototoxin Subst. Adj.
- Prototroph Subst.
- Prototrophic Adj.
- Prototropy Subst.
- Prototypal Adj.
- Prototype Subst. Verb Adj.
- Prototypic Adj.
- Prototypical Adj.
- Prototyping Subst. Adj.
- Protovertebral Adj.