Where does “post-doc” come from?

post-doc (English) comes from English post, from Middle French poste, from Italian posta, from Latin probāre, from Latin probō, from Latin Probus, from Proto-Indo-European pro-bhwo-, from Proto-Indo-European pro- — passed , crossed.

Ancestry of “post-doc”, step by step

post-doc traces back through two separate lines of ancestry.

via English post

StepLanguageWordMeaning
1EnglishpostA long dowel or plank protruding from the ground;...
2Middle Frenchposte
3Italianpostamail, post; post office; stakes
4Latinprobāre
5Latinprobōto approve, permit, commend
6LatinProbusgood, serviceable, excellent, superior, able
7Proto-Indo-Europeanpro-bhwo-being in front, prominent
8Proto-Indo-Europeanpro-toward, forward
9Proto-Indo-Europeanpor-to give birth; forward, through; going, passage
10Proto-Indo-Europeanper-before, in front; first; to go through
11Proto-Indo-Europeanpr̥tóspassed , crossed

via English DOC

StepLanguageWordMeaning
1EnglishDOCInitialism of drug of choice; Initialism of...
2EnglishdoctorA physician; a member of the medical profession;...
3Middle Englishdoctourdoctor
4Anglo-NormandoctourAlternative spelling of doctur
5Latindoctorteacher, instructor; catechist
6Latin-tor-er
7Proto-Italic-tōrForms agent nouns to verb stems
8Proto-Indo-European-tōrDerives agent nouns from verbs, denoting someone...
9Proto-Indo-European-tor-s
Every word from Proto-Indo-European pr̥tósEvery word from Proto-Indo-European per-Every word from Proto-Indo-European por-