Is glass a liquid?

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Is glass a liquid? how?

Yes.

No, though at one point it was.

Yes, a very viscous one. The glass in the windows of old churches is thicker at the bottom then at the top because it has slowly run down the pane.

Well, it depends on your exact definition of 'liquid' (there are things, like half-molten Jello, silly putty or cake mix, that aren't unambiguously one or the other). If you use the rheological definition (it measurably flows under any shear you can measure) then for practical purposes it is a solid (if you could carry out the experiment for a very, very long time, it would flow and be a viscoelastic fluid, at even longer time scales it would just be a supercooled liquid).
If you use a molecular definition, then glass is a type of liquid (dense state with short range order but no long-range order - in the case of glass, it would eventually form an ordered state, but in practice this takes too long).
Incidentally, in materials science the word 'glass' is often used to refer to dense non-equilibrium state with no long-range order but short-range order (of which window glass would be an example, but not the only one).
Many substances have complicated phase behaviour, like multiple solid states, or are viscoelastic, have yield stresses (toothpaste, mayonnaise) or have no clear-cut boiling transition between liquid and gas, so that rheologists and materials scientists often don't use labels like 'liquid' or 'solid' much but use more elaborate ways of characterising a substance's mechanical properties (flow curves, loss and storage moduli, etc).

Man; hard to top that last answer. I doff my chapeau.

But . . . I remember a citation from one of my very favorite sources, Unca Cecil from the Straight Dope. He replies:

Why arn't there panes where they are thicker at other sides, such as the top or corners? Although they used to stretch out the glass rather than squeeze it, it still wouldn't explain the inches in thickness difference from bottom to top of the pane.
Im sure ive read somewhere they add thickeners or crystalising agents to slow this "morphing" down. Im sorry i cant be bothered to cite it

I was surprised when I learned this...I think it was my chemistry teacher who told our class this year.

Glass has a melting point that is very low, that means it can be cold enough to freeze water and yet the glass will still not be solid. It is a liquid in my mind and as I understand one reason why it does not shatter whenever it vibrates to a point, if it was a real solid it would shatter everytime it vibrated, thats so much that their would be no intact glass on Earth. I read this in a science book in 8th grade, I cant remember exactly the reason why.

I think the fact that glass is used to hold acids, and that it safely does so, is powerful evidence for it being a liquid.
Acid will not eat through glass. Why else could that be?

This is one of the most common myths that is taught. Just goes to show you should never just take what somebody says as gospel truth.

Liquid is also different from fluid. Nobody said it was a liquid. Not even gels are considered liquids.