a suffix with the same meaning and properties as -an; -ian, is now the more productive of the two suffixes in recent coinages, especially when the base noun ends in a consonant: Orwellian; Washingtonian .
Origin
extracted from L loanwords in which -ānus-an is joined to stems ending in i
British Dictionary definitions for -ian
-an
suffix
1.
(forming adjectives and nouns) belonging to or relating to; a person belonging to or coming from: European
2.
(forming adjectives and nouns) typical of or resembling; a person typical of: Elizabethan
3.
(forming adjectives and nouns) adhering to or following; an adherent of: Christian
4.
(forming nouns) a person who specializes or is expert in: dietitian, phonetician