The most common and most likely answer to this crossword clue is the 7 letter word PIZZAZZ
P
I
Z
Z
A
Z
Z
More clues leading to the result PIZZAZZ
Buddy explains!

The straight part
We know that "Energy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case energy = pizzazz.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 PIZZAZZ mean?
PIZZAZZ noun- Flair, vitality, or zest; energy; vigor.