The most common and most likely answer to this crossword clue is the 11 letter word OUTNUMBERED
I've seen this crossword clue in The Guardian
O
U
T
N
U
M
B
E
R
E
D
Buddy explains!
The straight part
We know that "on the smaller side" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case on the smaller side = outnumbered.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 OUTNUMBERED mean?
OUTNUMBERED verb- (stative) to be more in number than somebody or something.