Where does “tercer” come from?

tercer (French) comes from Old French terce, from Latin tertia, from Latin tertius, from Latin trēs, from Proto-Italic trēs, from Proto-Indo-European *tréyes.

tercer (French): to plough a third time

Definitions

to plough a third time

Ancestry of “tercer”, step by step

Step	Language	Word	Meaning
1	Old French	terce	Alternative form of tiers
2	Latin	tertia	nominative feminine singular of tertius;...
3	Latin	tertius	third, the ordinal number after secundus and...
4	Latin	trēs	three; 3
5	Proto-Italic	trēs	three
6	Proto-Indo-European	*tréyes	—

Every word from Proto-Indo-European *tréyes →Every word from Proto-Italic trēs →Every word from Latin trēs →