diff --git a/docs/glossary.rst b/docs/glossary.rst
index 58b7d99..c8903a1 100644
--- a/docs/glossary.rst
+++ b/docs/glossary.rst
@@ -121,6 +121,9 @@
       Memory Tagging Extension. An optional Armv8.5 extension that enables
       hardware-assisted memory tagging.
 
+   LTS
+      Long-Term Support
+
    OEN
       Owning Entity Number