From Pluralpedia, the collaborative plurality dictionary
proinean (n., adj.)
Applies toheadmates, system functions

Proinean headmates are ones that are dormant and have been for a while. It is not certain whether or not a proinmate will return to the system or when. A group of headmates or subsystem may also be proinean, especially if their dormancy is linked and the whole group will collectively come out of dormancy at some point.