The most common and most likely answer to this crossword clue is the 10 letter word CENTIGRADE
I've seen this crossword clue in The Times
C
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The straight part
We know that "scale" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case scale = centigrade.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 CENTIGRADE mean?
CENTIGRADE noun- A centigrade temperature scale having the freezing point of water defined as 0° and its boiling point defined as 100° at standard atmospheric pressure. Known as the Celsius scale since 1948.
- A single degree on this scale.
- A unit of angle equal to the hundredth part of a quadrant. Its symbol is gon.
- (of a scale) Having 100 divisions between two fixed points.
- Celsius (since 1948).