The most common and most likely answer to this crossword clue is the 5 plus 10 letter word CAMEO APPEARANCE
C
A
M
E
O
A
P
P
E
A
R
A
N
C
E
Buddy explains!
The straight part
We know that "Notorious role for Hitchcock" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case notorious role for hitchcock = cameo appearance.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.