The most common and most likely answer to this crossword clue is the 9 letter word STRONGEST
I've seen this crossword clue in The Guardian
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More clues leading to the result STRONGEST
Buddy explains!
The straight part
We know that "the most powerful" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case the most powerful = strongest.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 STRONGEST mean?
STRONGEST adjective- Capable of producing great physical force.
- Capable of withstanding great physical force.
- (of water, wind, etc.) Having a lot of power.
- Determined; unyielding.
- Highly stimulating to the senses.
- Having an offensive or intense odor or flavor.
- Having a high concentration of an essential or active ingredient.
- (specifically) Having a high alcoholic content.
- (grammar) Inflecting in a different manner than the one called weak, such as Germanic verbs which change vowels.
- That completely ionizes into anions and cations in a solution.
- Not easily subdued or taken.
- Having wealth or resources.
- Impressive, good.
- Having a specified number of people or units.
- (of a disease or symptom) Severe; very bad or intense.
- Having a wide range of logical consequences; widely applicable. (Often contrasted with a weak statement which it implies.)
- (of an argument) Convincing.