As nouns the difference between xis and sis
is that
xis is plural of lang=en while
sis is shortened form of sister.
As an initialism SIS is
Secret Intelligence Service
xis
English
Noun
(head)
Anagrams
* (l)
----
sis
English
Initialism
(Initialism)
(head)
(British)
Synonyms
*
* Secret Intelligence Service
See also
* GCHQ
*
* SAS
* SBS
Anagrams
*
*