The most common and most likely answer to this crossword clue is the 9 letter word FIRMAMENT
I've seen this crossword clue in The Guardian
F
I
R
M
A
M
E
N
T
More clues leading to the result FIRMAMENT
- Heavens! Royal Mail has last word in fine computer systems
- Sky confusing extremes of modernism with fine art
- The last word in enduring time and space
- Intended to raise a tree metres higher in the sky
- Strong alpha males? Beginning to think this is heavenly
- Company changed name before start of takeover by Sky
- Tense after forceful last word? Heavens above!
- Adamant conclusion to prayer beginning to touch the heavens above
- Company meant to broadcast Sky
- Strong chaps in a tournament principally, site for stars?
Buddy explains!
The straight part
We know that "Sky" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sky = firmament.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 FIRMAMENT mean?
FIRMAMENT noun- (usually uncountable) The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, the sky.
- The field or sphere of an activity or interest.
- In the geocentric Ptolemaic system, the eighth celestial sphere which carried the fixed stars; (by extension) any celestial sphere.
- (obsolete except biblical) The abode of God and the angels; heaven.
- A piece of jewellery worn in a headdress with numerous gems resembling stars in the sky.
- A basis or foundation; a thing which lends strength or support.
- The act or process of making firm or strengthening.