[Easy E]

Professor? 

Also, is there a word/prefix like Doctor that isn't using it in the medical sense? 

So, what are your suggestions? 

[MarcoSkoll]

Professor?

As I suggested on Ammobunker, there probably isn't a fixed term.

There are some interesting synonyms (or close to it) like Preceptor, Pedagogue, Docent or Licentiate you could use though.

Also, is there a word/prefix like Doctor that isn't using it in the medical sense?

If I permit myself to reference Abnett, Aemos masquerades as Doctor Savine, a metallurgist, on Cinchare (I think that's Malleus) - there is therefore some precedent for the term being used for non medical learnedness.
(I'd say the medical sense would often be replaced by "Medicae", anyway).

Even if not, I use "Doctor" myself. Inquisitor Lyra Rhodes is also Doctor Rhodes due to her doctorate in Archaeology (being very loosely inspired by Indiana Jones). She still lectures and writes papers on occasion, although all under pseudonyms.

[krenshar]

They're both Latin titles and almost universally used, which makes things awkward.  But if invented words are acceptable:

For doctor;

• Doseor (twisting the Latin doceo or 'I teach' with no regard for linguistic niceties)
• Gnostor (as in gnosis)
• Lectune (playing with lektor, a Germanic word used in Denmark for the university lecturer rank below professor)
• Academ or Academician (the former could also serve as the abbreviation of the latter)

All I've thought of to add to Marco's suggestions for 'professor' is academarch - again not a real word.

[Edit]  There's also Meister or it's source Magister (Latin for teacher) although the latter might confuse if you use Magistratum for a planetary police force. [/Edit]

[DapperAnarchist]

"Lecturer" is a real university title, in the UK at least. It's any academic staff above researcher and below Professor (which in the UK is a specific rank, not a general title for 3rd level teachers).

[Easy E]

Thanks guys, that helps a lot.  If anyone else would liek to chime in, please keep it coming.  I was thinking something along Schola Primaris might fit as a title as well, but that sound smor elike a school rather than a position.   

Also, is there an Imperial equivalnet for "Junior"? 

In this case, I was thinking in Roman history they talked about Pliny the Elder and Pliny the Younger.  However, are there examples you can think of that are documented in GW canon, or do we have to get creative again? 

[Koval]

I suppose "Minoris" would work for "junior". So I imagine a lower-ranking academic doctory type might have a title a bit like "Lector Minoris".

[Easy E]

I mean "Junior" more in the sense of Joe Bob Briggs Jr. and not Junior Officer.   

[MarcoSkoll]

We don't get a lot of generational suffixes in British culture, and as that's the environment amongst which WH40K was written, it's probably not that common in the Imperium either.

As I experience it, "Junior" is far more American than it is British or European. I guess your closest Imperial styled version is the Roman approach: "Secundus", in the same manner as someone might be "Joe Bloggs the Second" .("The Second" is, in of itself, probably also passable).

These are perhaps slightly fancy, but the most traditional uses of generational suffixes in Europe would be as part of monarchy, nobility or (slightly related) the Pope. So it is something I'd think of being used in hive spires, not hive sumps.

[DapperAnarchist]

Rewinding a bit - "Reader" is the meaning of "Lector", the root of "Lecturer" and "Lektor". It's also used in Oxbridge colleges as a specific role or title, which Prachett makes extensive use of - the Reader in Unusual Runes, and the like.