Meaning of -ISH in English
■ suffix forming adjectives:
1》 (from nouns) having the qualities or characteristics of: girlish.
↘of the nationality of: Swedish.
2》 (from adjectives) somewhat: yellowish.
↘ informal denoting an approximate age or time of day: sixish.
OE -isc , of Gmc origin.
■ suffix forming verbs such as abolish .
from Fr. -iss- (from stems of verbs ending in -ir ), from L. -isc- (suffix forming inceptive verbs).
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004