I take it you're being sarcastic.

Perhaps my English is letting me down, but besides clothing buttons (and also the US word for what British English calls a "badge") I've never heard "button" used for anything that you can't communicate with by pushing it.

I guess you could communicate with me by pushing my bellybutton, but I wouldn't be 100% sure what you were trying to say.

:) However, would you call your bellybutton a "button"? I think it's a compound noun where "button" can't stand on its own in a meaningful way.

That's the most mean comment I've seen in this thread. Bellybutton:Button::Button:{Butt/On}

What's the nubbin on the end of a fencing foil called?

Spherical mushrooms are buttons. So is the round thing on the poker table that shows who the current dealer is.

Which English speaking world are you from? Because fasteners and 'things you push' yeah. Round things in general though? no. Knob maybe... maybe.

I'm from the US. The article was from the BBC. So that's two English-speaking countries.

In the US, of course, there are other buttons than push-buttons and clothing-buttons. Belly buttons for example. "Pin-back buttons" are usually just called buttons. Cornflowers are sometimes known as "Bachelor's button." You can of course use the term as an adjective -- button mushrooms, a button nose -- and you can refer to that indented mat that stops you from falling in the shower as a "button mat." If I described a "button mouse" to you, as opposed to a mouse button, you would probably come up with a visual image of a trackpoint mouse -- though you might also imagine a normal mouse covered with too many interaction buttons. The word "button" can also be used for things which are just generally small and globular and attached to other things -- you can find many search results for "button of rubber" and somewhat fewer for "button of glass" which fit this description.

My understanding of British English is that they would not call something a "knob" in polite company. Americans (and I am one) think nothing of it. So, there are a decent amount of words with slightly different meanings throughout the English speaking world.

Plenty of British English speakers would use the word "knob", for example I have no idea what I would call the knobs on the cooker other than knobs.

Or the knobs on amplifiers, or door knobs - well I suppose door handle works but door knobs are distinctly different from handles in my mind.

dial :)

Hmm yes perhaps, I tend to think of a dial as part of a measurement device. So a volt/ammeter has a dial, a clock has a dial etc.

I suppose I could see myself calling the temperature setting of a cooker the "Temperature dial", but not the mode selector knob thing. Mode/Temperature selector is quite a good one actually. Still doesn't come to hand like knob does though.

Indeed. I changed the buttons on my car just last week. They were getting flat.

Sounds like a pain, especially if you have locking lug buttons.

Just look forward to ordering a big button afterwards, from Dominos.

It's more like a spinning toothpaste lid. I wouldn't call that a button, even if it is round. And I can think of a lot of other round things which make no sense being called a button.