The most common and most likely answer to this crossword clue is the 10 plus 5 letter word COLLECTIVE NOUNS
I've seen this crossword clue in Financial Times
C
O
L
L
E
C
T
I
V
E
N
O
U
N
S
More clues leading to the result COLLECTIVE NOUNS
Buddy explains!
The straight part
We know that "stand and watch, maybe" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stand and watch, maybe = collective nouns.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.