The most common and most likely answer to this crossword clue is the 10 letter word CLINOMETER
I've seen this crossword clue in Financial Times
C
L
I
N
O
M
E
T
E
R
Buddy explains!

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 CLINOMETER mean?
CLINOMETER noun- An apparatus for measuring a vertical angle, a slope, or the height of a large object (e.g. a tree).