The most common and most likely answer to this crossword clue is the 6 letter word STURDY
I've seen this crossword clue in The Guardian
S
T
U
R
D
Y
More clues leading to the result STURDY
- Well-built chair finally installed in workplace
- Firm resistance: read all about it
- Solid work at University perhaps involves Republican
- Strong beer, ultimately, with which to fill mug up
- Firm dropping case of security guards
- Tough 24 hours without answers
- Think about head of rival firm
- Substantial scrapyard split into three parts!
- Robust rule observed in musical composition
- Research leader in survey is resolute
Buddy explains!

The straight part
We know that "resolute" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case resolute = sturdy.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 STURDY mean?
STURDY noun- A disease in sheep and cattle, caused by a tapeworm and marked by great nervousness or by dullness and stupor.
- Of firm build; stiff; stout; strong.
- Solid in structure or person.
- Foolishly obstinate or resolute; stubborn.
- Resolute, in a good sense; or firm, unyielding quality.