Morphological process for derivation of the word "ish" from suffix "-ish"?
Solution 1:
Ish is listed in the OED as colloquial, first used 1986, and defined:
Qualifying a previous statement or description, esp. as a conversational rejoinder: almost, in a way, partially, vaguely.
It's also listed in at least some of these dictionaries, including Collins:
(slang) used to express reservation or qualified assent ⇒ Things are looking up. Ish