The most common and most likely answer to this crossword clue is the 7 letter word SPARKLE
I've seen this crossword clue in Independent
S
P
A
R
K
L
E
More clues leading to the result SPARKLE
- Author Muriel has the French fizz
- Odds on racehorse are glittering
- Deer knocks up glitter
- Deer knocks back glitter
- Dispute over cabbage lacking a shine
- Say ‘Boom’! – a setback for moose in animation
- Around a thousand scattered pearls glisten
- Kuala Lumpur’s involved in free energy
- Second stop in NCP, say, by learner with electronic dash
- Odds on champion horse showing winning quality?
Buddy explains!

The straight part
We know that "glisten" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case glisten = sparkle.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 SPARKLE mean?
SPARKLE noun- A little spark; a scintillation.
- Brilliance; luster.
- Liveliness; vivacity.
- The quality of being sparkling or fizzy; effervescence.
- To emit sparks; to throw off ignited or incandescent particles
- (by extension) To shine as if throwing off sparks; to emit flashes of light; to scintillate; to twinkle
- To manifest itself by, or as if by, emitting sparks; to glisten; to flash.
- To emit little bubbles, as certain kinds of liquors; to effervesce
- To emit in the form or likeness of sparks.
- To disperse.
- To scatter on or over.