If something is mouldering, it is decaying slowly where it has been left.
例句
...one of your scripts that's been mouldering under the bed for ages...你的一部在床下尘封已久已经开始腐烂的书稿It is clear that such ideas will be left to moulder.明摆着,这些想法将无人问津。
英英词典释义
Adjective
1. becoming rotten;
"a field covered with thousands of decomposing bodies""John Brown's body lies a-moldering in the grave"