- subset of a space of unspecified type which respects its structure
- fictional property of space time
“They’re only stable in subspace,” Picard said, “so evidence of their effects indicates that a subspace phenomenon occurred nearby.”
- fictional means of communication
2012:
V’Las would send coded signals over subspace, which would then be decoded and transcribed on documents for the Romulan leaders.
[Star Trek Federation: The First 150 Years]