The definition of a nuclear membrane is a double-layered lining that encloses a cell nucleus and allows certain molecules to pass through.
An example of a nuclear membrane is inner and outer membrane of a cell.
the double-layered membrane of the cell nucleus, separating the nucleoplasm from the cytoplasm and permeable to certain molecules, esp. DNA, RNA, and ATP
now often nuclear envelope
The double-layered membrane enclosing the nucleus of a cell. Also called nuclear envelope.