Nan is a synonym of gran.
As nouns the difference between gran and nan
is that gran is a grandmother while nan is affectionate name for a grandmother.
As a proper noun Nan is
{{given name|female|diminutive=Ann}} and Nancy.
As an initialism NAN is
NMDA Antagonist Neurotoxicity.
gran
English
Noun
(
en noun)
(informal, usually affectionate) a grandmother
(rare) a grandfather
nan
English
Etymology 1
Possibly derived from a (etyl) language.
Noun
(
en noun)
(British) Affectionate name for a grandmother.
Synonyms
* nana
* nanna
Etymology 2
From (etyl) .