Adding custom / registry source terms to glossary (#12430)

docs-v2/pages/glossary.mdx

@@ -110,6 +110,10 @@ Pipedream charges one credit per 30 seconds of compute time at 256MB megabytes o
 
 By default, [HTTP endpoints](#http-endpoint) are served from the `*.m.pipedream.net` domain. You can configure a [custom domain](/workflows/domains) if you want to host that endpoint on your own domain.
 
+### Custom source
+
+An [event source](#event-source) that you create using custom code, or by modifying a [registry source](#registry-source).
+
 ## D
 
 ### Data retention
@@ -378,6 +382,10 @@ The [builder](#builder) UI that allows you to search objects [exported](#export)
 
 Synonym for [component registry](#component-registry).
 
+### Registry source
+
+An [event source](#event-source) available in the [component registry](#component-registry). Registry sources are reviewed and approved by Pipedream.
+
 ## S
 
 ### Schedule trigger