Latin, means disjoint or scattered members or parts. The phrase is used for speaking of fragments of a formerly whole body of knowledge which has been scattered into often hard to recognize bits and pieces by the process of transmission or deliberate obfuscation. In this state the original meanings and context have been lost.
For example, the elements of the Grail ensemble, such as the sword, the cup and lance may be disjecta membra of ancient science or technology. The legends may be disjecta membra of formerly known esoteric practices and archetypes of spiritual evolution.