The most common and most likely answer to this crossword clue is the 14 letter word ANTHROPOLOGIST
I've seen this crossword clue in Independent
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More clues leading to the result ANTHROPOLOGIST
- Nothing improper about his subject, decreed Pope
- One making a defence about name through expert in human affairs
- Scientist‘s introduction to rare work included by one making literary selection
- Scientist moving north, engaged by defence expert
- Social scientist reading, perhaps, work held by literary collector
- Investigator of people in North mistreated, needing defender around
Buddy explains!

The straight part
We know that "Scientist" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case scientist = anthropologist.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ANTHROPOLOGIST mean?
ANTHROPOLOGIST noun- One who is versed in anthropology.