The most common and most likely answer to this crossword clue is the 5 letter word GLAZE
I've seen this crossword clue in The Daily Telegraph
G
L
A
Z
E
More clues leading to the result GLAZE
- Grand to do nothing but mend broken windows
- Peer astride entrance to Lords in coat
- Polish crop changing hands
- Peer outside entrance to Lords in coat
- Good loaf icing
- Fit windows in government lounge
- Put coating on top of granary loaf
- Top of granary loaf must be a shiny coating
- Look to secure large coat
- Give a reflective look, a steady one, taking in lake
Buddy explains!

The straight part
We know that "a shiny coating" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a shiny coating = glaze.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 GLAZE mean?
GLAZE noun- The vitreous coating of pottery or porcelain; anything used as a coating or color in glazing. See glaze (transitive verb).
- A transparent or semi-transparent layer of paint.
- A smooth edible coating applied to food.
- A smooth coating of ice formed on objects due to the freezing of rain; glaze ice.
- Broth reduced by boiling to a gelatinous paste, and spread thinly over braised dishes.
- A glazing oven; glost oven.
- To install windows.
- To apply a thin, transparent layer of coating.
- To become glazed or glassy.
- For eyes to take on an uninterested appearance.