The most common and most likely answer to this crossword clue is the 3 plus 5 letter word EGG WHITE
I've seen this crossword clue in The Daily Telegraph
E
G
G
W
H
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T
E
More clues leading to the result EGG WHITE
- Get weight reduced somehow — one component of breakfast food?
- Say Bush Jr attacked Spain; how slimy is that?
- Get weight reduced somehow — cook using this
- Meringue ingredient for example affected weight
- Meringue material, for instance, affected weight
- Ingredient of meringue, for example, with weight adjusted
- Say snooker player pots green at first — not the yellow
- Urge chess player to get the outer part of a bull's eye
Buddy explains!

The straight part
We know that "Ingredient of meringue" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ingredient of meringue = egg white.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 EGG WHITE mean?
EGG WHITE adjective- Having the color of egg whites.
- Made of egg whites.