The most common and most likely answer to this crossword clue is the 6 letter word PRIMAL
I've seen this crossword clue in Independent
P
R
I
M
A
L
More clues leading to the result PRIMAL
- Chief’s friend grabbing skirt
- Formal answer length most important
- First mate biting lip
- First mate crossing border
- Chief place occupied by prince from the south
- First the French in revolution supporting puritanical
- Original friend across the border
- Kind of scream from mate holding on to edge
- Very important border in China
- China protecting border, first of all
Buddy explains!

The straight part
We know that "most important" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case most important = primal.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 PRIMAL mean?
PRIMAL noun- A primal cut (of meat).
- To take part in primal therapy.
- Being the first in time or in history.
- Of greatest importance; primary.
- (meat trade) Being one of the pieces of meat initially separated from the carcass during butchering, prior to division into smaller cuts.