The most common and most likely answer to this crossword clue is the 12 letter word INTRANSIGENT
I've seen this crossword clue in The Daily Telegraph
I
N
T
R
A
N
S
I
G
E
N
T
More clues leading to the result INTRANSIGENT
- Stubborn general being conveyed around
- Not accommodating endlessly travelling fellow
- Stubborn dope stopping on the way
- Refusing to move, nine starting to budge
- Determined current passing round grid, initially
- Diehard en route to collect data
- Is gran wavering in purpose? Far from it
- It’s tough, travelling without information
- Diehard on the way, carrying information
- Iran isn’t getting new arrangement with bloke being bloody-minded
Buddy explains!

The straight part
We know that "Obstinate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case obstinate = intransigent.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 INTRANSIGENT mean?
INTRANSIGENT noun- A person who is intransigent.
- Unwilling to compromise or moderate a position; unreasonable