- prot-
- combining form
or proto-
Etymology: Middle English protho-, from Middle French, from Late Latin proto-, from Late Greek prōt-, prōto-, from Greek, from prōtos; akin to Greek pro before, ahead — more at for1.a. : first in time
protohistoric
protonymph
b. : first in status : chief in rank or importance : principalprotocerebrum
protocone
c. : beginning : tending toward : giving rise toprotofascism
protoplanet
2. chemistrya. : first or lowest of a series : member of a series having or supposed to have the smallest relative amount of the element or radical indicated in the name to which it is prefixedprotoxide
protochloride
b. : substance held to be the parent of the substance to the name of which it is prefixedprotoactinium
c. : first or primary product of decompositionprotoproteose
3. biologya. : archetypalprotomorph
protonephros
b. : first formed : primaryprotoderm
protoxylem
4. usually capitalized : belonging to or constituting the recorded or assumed language that is ancestral to a language or to a group of related languages or dialects — usually spelled proto- and joined to a capitalized second element with a hyphenProto-Arabic
Proto-Indo-European
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var. of proto- before a vowel: protamine.* * *
prot-,Prot.,Protestant.* * *
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prot-the form of proto- used before a vowel.
Useful english dictionary. 2012.