The most common and most likely answer to this crossword clue is the 7 letter word SIMPERS
I've seen this crossword clue in The Daily Telegraph
S
I
M
P
E
R
S
More clues leading to the result SIMPERS
Buddy explains!
The straight part
We know that "smiles coyly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case smiles coyly = simpers.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 SIMPERS mean?
SIMPERS noun- A foolish, frivolous, self-conscious, or affected smile; a smirk.
- To smile in a foolish, frivolous, self-conscious, coy, or smug manner.
- To glimmer; to twinkle.