The most common and most likely answer to this crossword clue is the 4 letter word SASS
S
A
S
S
More clues leading to the result SASS
- Insolence from two Nazi groups
- Elite regiment’s foolish talk
- Cheek of son visiting famous regiment
- Sauce with special forces people to have drop of Spa
- Start to stroke animal's cheek
- Talk back to American army unit
- Lip salve and gloss not fully emptied
- Insolent behaviour implying no change in character?
- Singular bottom lip
Buddy explains!

The straight part
We know that "foolish talk" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case foolish talk = sass.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 SASS mean?
SASS noun- Backtalk, cheek, sarcasm.
- Vegetables used in making sauces.
- To talk, to talk back.
- To speak insolently to.