diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index e0e3739b08..59a05b9b2d 100644
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -604,7 +604,7 @@ typedef enum {
     VIR_DOMAIN_MEMORY_STAT_RSS             = 7,
 
     /*
-     * How big the balloon can be inflated without pushing the guest system
+     * How much the balloon can be inflated without pushing the guest system
      * to swap, corresponds to 'Available' in /proc/meminfo
      */
     VIR_DOMAIN_MEMORY_STAT_USABLE          = 8,
diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 413f8af5a4..4f083494e1 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -5987,7 +5987,7 @@ virDomainGetInterfaceParameters(virDomainPtr domain,
  * VIR_DOMAIN_MEMORY_STAT_AVAILABLE:
  *     The total amount of memory available to the domain's OS (in kb).
  * VIR_DOMAIN_MEMORY_STAT_USABLE:
- *     How big the balloon can be inflated without pushing the guest system
+ *     How much the balloon can be inflated without pushing the guest system
  *     to swap, corresponds to 'Available' in /proc/meminfo
  * VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON:
  *     Current balloon value (in kb).
diff --git a/tools/virsh.pod b/tools/virsh.pod
index 770ca49fab..9a2390563a 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -819,6 +819,8 @@ B<Explanation of fields>:
   available         - The amount of usable memory as seen by the domain (in kB)
   actual            - Current balloon value (in KB)
   rss               - Resident Set Size of the running domain's process (in kB)
+  usable            - The amount of memory which can be reclaimed by balloon
+without causing host swapping (in KB)
 
 For QEMU/KVM with a memory balloon, setting the optional I<--period> to a
 value larger than 0 in seconds will allow the balloon driver to return