The most common and most likely answer to this crossword clue is the 4 letter word LUMA
L
U
M
A
Buddy explains!
The straight part
We know that "Local units (monetary), Armenian primarily" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case local units (monetary), armenian primarily = luma.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 LUMA mean?
LUMA noun- A currency unit of Armenia, worth one hundredth of an Armenian dram.
- The brightness in an image, as opposed to the saturation or chroma.