A signal does not mean by itself. Meaning appears when the receiver stabilizes a relation between signal and experience.
Why this term exists
A registered difference is not automatically meaningful. Signal names what reaches a receiver; Meaning appears only when the receiver stabilises its relation to experience.
Definition in the system
An impulse, relation or pattern that can be registered by a receiver; it does not mean by itself.
Canonical boundary / operational note
Without the receiver's stabilised relation to prior interaction, memory or model, a signal may register as Sense without yet becoming Meaning.