The most common and most likely answer to this crossword clue is the 17 letter word STICKSÂ ANDÂ STONES
I've seen this crossword clue in The Guardian
S
T
I
C
K
S
Â
A
N
D
Â
S
T
O
N
E
S
Buddy explains!
The straight part
We know that "these really hurt" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case these really hurt = sticks and stones.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.