The most common and most likely answer to this crossword clue is the 3 plus 3 plus 4 plus 5 letter word CUT AND COME AGAIN
C
U
T
A
N
D
C
O
M
E
A
G
A
I
N
Buddy explains!
The straight part
We know that "abundant supply" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case abundant supply = cut and come again.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.