Where does “quīnquāgintā” come from?

quīnquāgintā (Latin) comes from Proto-Indo-European penkʷēḱomt, from Proto-Indo-European *pénkʷedḱomt.

Ancestry of “quīnquāgintā”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	penkʷēḱomt	—
2	Proto-Indo-European	*pénkʷedḱomt	—

quīnquāgintā — Etymology, Origin & Word History | Etymology Explorer