Where does “in posse” come from?

in posse (Latin) comes from Latin posse, from Latin potis, from Proto-Italic potis, from Proto-Indo-European pótis, from Proto-Indo-European ph₃tis, from Proto-Indo-European peh₃- — to drink.

Ancestry of “in posse”, step by step

in posse traces back through two separate lines of ancestry.

via Latin posse

StepLanguageWordMeaning
1Latinpossepresent active infinitive of possum  "to be able...
2Latinpotisable, capable, possible
3Proto-Italicpotismaster, in control of
4Proto-Indo-Europeanpótismaster, ruler; husband
5Proto-Indo-Europeanph₃tis—
6Proto-Indo-Europeanpeh₃-to drink

via Latin in

StepLanguageWordMeaning
1Latininin, at, on, upon, from; within, while in; into,...
2Old Latinenin
3Proto-Italicenin
4Proto-Indo-Europeanh₁énin

Words derived from “in posse”

Every word from Proto-Indo-European peh₃- →Every word from Proto-Indo-European ph₃tis →Every word from Proto-Indo-European pótis →