Learn how to say Moulder correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word moulder:
[no object] (often as adjective mouldering)
slowly decay or disintegrate, especially because of neglect:
the smell of mouldering books
I couldn’t permit someone of your abilities to moulder away in a backwater
mid 16th century: perhaps from mould3, but compare with Norwegian dialect muldra ‘crumble’
Spell moulder with -ou- in the middle (the spelling molder is American).