The most common and most likely answer to this crossword clue is the 7 letter word MOUTHED
I've seen this crossword clue in Financial Times
M
O
U
T
H
E
D
Buddy explains!
The straight part
We know that "Surreptitiously conveyed" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case surreptitiously conveyed = mouthed.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 MOUTHED mean?
MOUTHED verb- To speak; to utter.
- To make the actions of speech, without producing sound.
- To utter with a voice that is overly loud or swelling.
- To pick up or handle with the lips or mouth, but not chew or swallow.
- To take into the mouth; to seize or grind with the mouth or teeth; to chew; to devour.
- To form or cleanse with the mouth; to lick, as a bear licks her cub.
- To make mouths at.
- (in combination) Having a specified type of mouth.