what's the difference between "silly" and "dumb"

In this context, both work and mean roughly the same thing. Important to note, though, that silly is a more flexible word! If I said “that was a dumb movie,” that could mean something different from “that was a silly movie.”

All three are very similar in this context and would sound normal. Silly might suggest the waiting made you feel socially awkward ("I feel silly waiting for you while wearing this ridiculous hat") whereas dumb might suggest some aspect of it was easily avoidable ("I feel dumb waiting for you outside in this snowstorm when I could've stayed inside"). Foolish sounds slightly more formal and could imply either. But realistically no one will care about these very slight differences.

Dumb has the context on unintelligent… Silly is more funny… So a child saying here kitty kitty to a tiger is silly and not dumb…and adult doing it…is going to have people think “well that’s dumb”

Silly is happier Dumb is meaner Silly has a neutral/positive connotation Dumb has a negative connotation

I probably wouldn't say any of those three phrases, but what I would say depends entirely on the context. It's possible I might say "silly", but unlikely. If I was waiting for someone on the wrong day, I might say "I feel stupid for waiting", or "It was daft of me to wait". Like everything though, you'll get dozens of regional variations. In the UK, we don't often use the word "dumb" - that's mostly American. Likewise, I don't think Americans commonly use the word "daft". "foolish" is rather old-fashioned, and not very common (in my neck of the woods).

Silly = weird, but not in a bad way Dumb = mildly stupid

Silly is more about being immature, while dumb is more about being unwise.

I will add that “dumb” literally means mute or unable to speak. So you will sometimes get a pedant who is picky about that technical definition. If you want connotations of lack of intelligence, I would go with “stupid“ or “idiotic“ or your suggestion of “dumb“ though as noted there are literal definition issues with that word. If you want connotations of absurdity (like someone waiting for a date who they perceive as being “out of their league” or too amazing to want to date them.) you might use “foolish” or“silly“ or “unrealistic“, even.

I will agree with those saying that 'silly' is less serious and carries a "funny" connotation, while 'dumb' more so means 'stupid'.

Dumb is a negative word. Silly can be positive or negative. Dumb means stupid; silly means unserious and ineffectual.

Being English, I don’t use the word ‘dumb’.

They can mean the same thing, but in my experience (Midwest US) "silly" is more light-hearted while "dumb" is a little more mean. I also just like the word "silly" because I think it's a silly word. But tone has a lot of power, so "dumb" can just as easily be a more playful word, depending on how you say it and to whom you say it.

They mean pretty similar things in this context, and honestly both of those sentences would work fine, foolish could sound a bit odd. Although for little differences, I suppose silly has a more “funny” or “goofy” feel to it while dumb has a more negative tone overall

IMO Dumb is closer to stupid than silly.

Any of the above work just fine

Silly is like goofy of weird and dumb can mean the same thing but usually has a negative undertone so you wouldn’t use it if u liked something

Hmm. There's a lot of overlap,-maybe even complete overlap. Both can mean stupid or foolish. But dumb is closer to stupid and silly is closer to foolish. Dumb actions are rarely light hearted but silly ones often are. Wearing a reindeer antler hat and a red nose is silly. Refusing to wear a hat in subzero weather is dumb. Dressing like a Disney princess might be silly, but expecting people to treat you like one is dumb. Painting your car purple might be silly, but removing all the seat belts is dumb.