diff --git a/book/source/23-glossary.md b/book/source/23-glossary.md
index 8bf5b10..4819c9a 100644
--- a/book/source/23-glossary.md
+++ b/book/source/23-glossary.md
@@ -24,6 +24,11 @@ Authentication Tag
 Authenticity
     See {term}`Authentication`.
 
+Binding Signature
+    A {term}`signature` on a {term}`component` which links that {term}`component` to a {term}`certificate<OpenPGP Certificate>`.
+    
+    See {ref}`binding_sigs` for more.
+
 CA
     See {term}`Certification Authority`.
 
@@ -89,7 +94,7 @@ Encryption Key Flag
     A {term}`Key Flag`, indicating that a {term}`Component Key` can be used for encrypting data. See [](capabilities_key_flags).
 
 Expiration
-    A mechanism by which a {term}`Component` is invalidated due to the {term}`Expiration Time` of its binding signature being older than the {term}`Reference Time` by which it is validated.
+    A mechanism by which a {term}`Component` is invalidated due to the {term}`Expiration Time` of its {term}`binding signature` being older than the {term}`Reference Time` by which it is validated.
 
 Expiration Date Subpacket
     An {term}`OpenPGP Signature Subpacket Type` which defines the {term}`Expiration Time` for an {term}`OpenPGP Signature Packet`.