It's a word you need to understand, but not to use. However, here's an example of use. "My friend is snobbish about coffee. Dunkin' Donuts coffee isn't good enough for him. It has to be single estate Colombian Supremo, and he has to grind it himself and make it in a French press." Did you see it in F. Scott Fitzgerald's "The Great Gatsby?" "I am still a little afraid of missing something if I forget that, as my father snobbishly suggested, and I snobbishly repeat, a sense of the fundamental decencies is parcelled out unequally at birth." The idea that something is "parcelled out unequally at birth" means that people are born unequally, some are born better than others. That's a snobbish idea.

What was the father's suggestion? Something about the suggestion struck the daughter as snobbish, but without knowing what he said we can't provide much help.

snobbishly would be how a snob behaves and the intonation they place on what they say, meaning it is not what you say but how you say it, a snob looks down on other people, they think they are better than common people, just that are generally condescending, and insulting and that is how they talk to people, like they are better than everyone, no one is as good as they are.

This means that she thinks her father's suggestion is a snobbish one. A snobbish person is one who only likes rich or titled people.