Proto-Indo European
— Navneord
– Engelsk
～ a prehistoric unrecorded language that was the ancestor of all Indo-European languages
proto-oncogene
— Navneord
– Engelsk
～ a normal gene that has the potential to become an oncogene
Proto-Norse
— Navneord
– Engelsk
～ the Germanic language of Scandinavia up until about 700
proto
— Tillægsord
– Engelsk
～ indicating the first or earliest or original; "`proto' is a combining form in a word like `protolanguage' that refers to the hypothetical ancestor of another language or group of languages"
protoactinium
— Navneord
– Engelsk
～ a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
protoanthropology
— Navneord
– Engelsk
～ the study humans prior to the invention of writing
protoarchaeology
— Navneord
– Engelsk
～ the study of prehistoric human artifacts and human fossils