Update docs/general/glossary.md

Co-authored-by: Radha <86818441+DrW3RK@users.noreply.github.com>

docs/general/glossary.md

@@ -468,7 +468,7 @@ A unique numeric (non-negative integer) identifier for a parachain.
 
 ## Parathread
 
-A parathread can have two meanings: a substrate-based chain not yet parachain (i.e. not connected to
+Historically, the term "parathread" has been used in two contexts: a substrate-based chain not yet parachain (i.e. not connected to
 a {{ polkadot: Polkadot :polkadot }}{{ kusama: Kusama :kusama }} core), or a on-demand parachain
 (i.e. a parachain using instantaneous coretime).