The most common and most likely answer to this crossword clue is the 11 letter word EMOTIONLESS
I've seen this crossword clue in The Times
E
M
O
T
I
O
N
L
E
S
S
More clues leading to the result EMOTIONLESS
Buddy explains!
The straight part
We know that "cool, calm and collected" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cool, calm and collected = emotionless.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 EMOTIONLESS mean?
EMOTIONLESS adjective- Lacking emotion.