The most common and most likely answer to this crossword clue is the 8 letter word SEESAWED
I've seen this crossword clue in The Times
S
E
E
S
A
W
E
D
Buddy explains!
The straight part
We know that "as kids in playground did?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case as kids in playground did? = seesawed.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 SEESAWED mean?
SEESAWED verb- To use a seesaw.
- (by extension) To fluctuate.
- To cause to move backward and forward in seesaw fashion.