The most common and most likely answer to this crossword clue is the 9 letter word MONOLITHS
I've seen this crossword clue in Financial Times
M
O
N
O
L
I
T
H
S
More clues leading to the result MONOLITHS
Buddy explains!
The straight part
We know that "Stonehenge, say" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stonehenge, say = monoliths.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 MONOLITHS mean?
MONOLITHS noun- A large, single block of stone which is a natural feature; or a block of stone or other similar material used in architecture and sculpture, especially one carved into a monument in ancient times.
- Anything massive, uniform, and unmovable, especially a towering and impersonal cultural, political, or social organization or structure.
- A substrate having many tiny channels that is cast as a single piece, which is used as a stationary phase for chromatography, as a catalytic surface, etc.
- A dead tree whose height and size have been reduced by breaking off or cutting its branches.