The most common and most likely answer to this crossword clue is the 2 plus 8 letter word NO NONSENSE
I've seen this crossword clue in Financial Times
N
O
N
O
N
S
E
N
S
E
Buddy explains!
The straight part
We know that "simple and straightforward/simple and straightforward" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case simple and straightforward/simple and straightforward = no nonsense.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 NO NONSENSE mean?
NO NONSENSE adjective- Practical, not concerning oneself with anything silly or unimportant.