Earliest ancestor

• An ancestor in the direct line

Wiktionary Word definitions in Wiktionary
n. An initial ancestor.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"an ancestor," late 15c., from Medieval Latin primogenitor , from Latin primo (adv.) "first in order of time; at first," from primus "first" (see prime (adj.)) + genitor "father," from genitus , past participle of gignere "to beget" (see genus ). Related: ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Primogenitor \Pri`mo*gen"i*tor\, n. [LL., fr. L. primus first + genitor a begetter.] The first ancestor; a forefather.

WordNet Word definitions in WordNet
n. an ancestor in the direct line [syn: progenitor ]