The most common and most likely answer to this crossword clue is the 8 letter word MUNCHKIN
I've seen this crossword clue in The Times
M
U
N
C
H
K
I
N
More clues leading to the result MUNCHKIN
Buddy explains!

The straight part
We know that "Cute American kid" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cute american kid = munchkin.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 MUNCHKIN mean?
MUNCHKIN noun- A domestic cat breed with short legs.
- The empty space in the center of a donut.
- A small ball-shaped pastry, made in the same manner as a donut, roughly the size of the hole in a donut.
- (welfare) An income bracket where one is without benefits, even though benefits are available in the next lower and next higher brackets.
- A section of water for which no one has fishing rights that is completely surrounded by regions where various parties hold fishing rights.
- A child.
- A person of very short stature.
- A player who mainly concentrates on increasing their character's power and capabilities.