The most common and most likely answer to this crossword clue is the 8 letter word INHUMANE
I've seen this crossword clue in The Times
I
N
H
U
M
A
N
E
More clues leading to the result INHUMANE
- Callous article suppressed by popular philosopher
- Cruel and senseless to inhibit what bees do
- Stupid bears smell beastly
- Drone – boring, senseless, cruel
- Cruel article found in Bury
- Fashionable aspect conceals fellow acting like a beast
- One old lady inhales bad smell close to Robbie Savage
- Cool shade keeps chap cold inside
- Cruel but popular chap put in shade
- Cruel and stupid about bad smell
Buddy explains!

The straight part
We know that "Callous" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case callous = inhumane.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 INHUMANE mean?
INHUMANE adjective- Lacking pity or compassion for misery and suffering; cruel, unkind, not humane.