Probate
late Middle English: from Latin probatum ‘something proved’, neuter past participle of probare ‘to test, prove’.
wiktionary
From Middle English probate, from Latin probatus, past participle of probare(“to test, examine, judge of”); see probe, prove.
etymonline
probate (n.)
in law, "official proving of a will," mid-15c., from Medieval Latin legalese use of Latin probatum "a thing proved," neuter of probatus "tried, tested, proved," past participle of probare "to try, test, prove" (see prove).
probate (v.)
1560s, "to prove" (a general sense now obsolete), from probate (n.) or from Latin probatus, past participle of probare "to make good; esteem, represent as good; make credible, show, demonstrate; test, inspect; judge by trial." Specific sense of "prove the genuineness of a will" is from 1792. Related: Probated; probating.