Element of seaming movement with Underwood's first maiden (9)
I believe the answer is:
magnesium
'element' is the definition.
(magnesium is a kind of element)
'seaming movement with underwood's first maiden' is the wordplay.
'movement with' indicates anagramming the letters.
'first' indicates taking the first letters.
'maiden' becomes 'm' (cricket abbreviation).
The first letter of 'underwoods' is 'u'.
'seaming' mixed up with 'u' gives 'magnesiu'.
'magnesiu'+'m'='MAGNESIUM'
'of' is the link.
(Other definitions for magnesium that I've seen before include "flammable element" , "Silver-white metallic element" , "Metal element, Mg" , "Silvery-white metallic element" , "member of a second group" .)