Could somebody please explain

1) what does "9-ish" means when somebody is trying to say time;

2) and what are the effect(s) when you add "-ish" at the end of a word.

ish is a very informal way of saying approximately or around.

so 9-ish means around 9 o'clock rather than precisely at 9 o'clock. If someone was coming to see me at 9ish I'd expect them sometime between about 8.40 and 9.20.
The suffix -ish means like, almost like, similar to. It is most common with color adjectives: yellowish, whitish, blackish, reddish, grayish, ...
It is added to some nouns: womanish, mannish, girlish, boyish, shrewish, oafish, boorish, elfish, impish, foolish, clownish, snobbish, prudish, hellish, devilish, mulish, freakish

It is used to form nationality or ethnic group names in a very few cases: Flemish, Danish, Finnish, Spanish, Jewish, Yiddish
It is also a verb suffix related to the Romance language "ir" verbs: furnish, banish, punish, diminish, replenish, brandish, vanish, embellish, ... (Here it does not mean like or similar.)

In many cases it is not a suffix, but part of the root of the word. radish, rubbish, dish, fish, fetish, parish, wish

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Thank you for your comment. I'm Portuguese speaker and at the first time I've read a good and simple definition of ISH.
Students: We have free audio pronunciation exercises.