The most common and most likely answer to this crossword clue is the 9 letter word MAGNESIUM
M
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More clues leading to the result MAGNESIUM
- The old woman hugging girl, one member of a second group
- Girl one going among silent element
- Metal tops for each stopper I placed in large bottle
- Element of seaming movement with Underwood’s first maiden
- Metal guineas melted down in empty museum
- Bottle containing tablets
- Odd bits removed, see ship in bottle that’s silvery-white
- Metal core of worm gear should expand
- De Mille and I captivated by silent fireworks material
- Element amusing me getting drunk
Buddy explains!

The straight part
We know that "that’s silvery-white" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case that’s silvery-white = magnesium.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 MAGNESIUM mean?
MAGNESIUM noun- The chemical element (symbol Mg) with an atomic number of 12. It is a light, easily flammable, silvery-white alkaline earth metal.