proto-
combining form
variants or before a vowel prot-
1
a
: first in time
protohistory
b
: beginning : giving rise to
protoplanet
2
: parent substance of a (specified) substance
protactinium
3
: first formed : primary
protoxylem
4
capitalized : relating to or constituting the recorded or assumed language that is ancestral to a language or to a group of related languages or dialects
Proto-Indo-European
Word History
Etymology
Greek prōt-, prōto-, from prōtos; akin to Greek pro before — more at for