The most common and most likely answer to this crossword clue is the 8 letter word ZILLIONS
I've seen this crossword clue in The Sunday Telegraph
Z
I
L
L
I
O
N
S
More clues leading to the result ZILLIONS
Buddy explains!

The straight part
We know that "Huge number" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case huge number = zillions.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 ZILLIONS mean?
ZILLIONS noun- An unspecified large number (of); a gazillion.