The most common and most likely answer to this crossword clue is the 3 plus 5 letter word PIN MONEY
I've seen this crossword clue in The Daily Telegraph
P
I
N
M
O
N
E
Y
More clues leading to the result PIN MONEY
Buddy explains!
The straight part
We know that "a little extra to spend" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a little extra to spend = pin money.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 PIN MONEY mean?
PIN MONEY noun- An allowance of money given by a man to his wife or to other dependents for their personal, discretionary use.
- A relatively small sum of cash kept in one's personal possession for routine expenses or incidental purchases; an amount of money which is not particularly significant.