prot-

1.
variant of proto- before a vowel:
protamine.
British Dictionary definitions for prot-

prot-

combining form
1.
a variant of proto-

proto-

combining form
1.
indicating the first in time, order, or rank: protomartyr
2.
primitive, ancestral, or original: prototype
3.
indicating the reconstructed earliest stage of a language: Proto-Germanic
4.
indicating the first in a series of chemical compounds: protoxide
5.
indicating the parent of a chemical compound or an element: protactinium
Word Origin
from Greek prōtos first, from pro before; see pro-²
prot- in Medicine

prot- pref.
Variant of proto-.