The most common and most likely answer to this crossword clue is the 7 letter word KICKOFF
K
I
C
K
O
F
F
Buddy explains!
The straight part
We know that "Start" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case start = kickoff.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 KICKOFF mean?
KICKOFF noun- The opening kick of each half of a game of football.
- (by extension) the opening sequence of any event