I. mol ‧ der /ˈməʊldə $ ˈmoʊldər/ BrE AmE verb [intransitive]
[ Date: 1500-1600 ; Origin: Probably from mold 'earth' (11-21 centuries) , from Old English molde ; influenced by ↑ mold 1 (1) ]
the American spelling of ↑ moulder
II. moul ‧ der BrE AmE British English , molder American English /ˈməʊldə $ ˈmoʊldər/ ( also moulder away ) verb [intransitive]
to decay gradually:
old papers mouldering away in the attic