The most common and most likely answer to this crossword clue is the 12 letter word SOFT-HEARTED
I've seen this crossword clue in The Guardian
S
O
F
T
-
H
E
A
R
T
E
D
Buddy explains!

The straight part
We know that "kind" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case kind = soft-hearted.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.
Crossword Answer definitions
SOFT-HEARTED adjective- Gentle; kind; sympathetic.
- Easily moved to sorrow or pity.
- Willing to accept criticism.