Toothpaste is technically a liquid. Even glass window panes are technically considered a liquid. Any time the mass remains pliable and can shift, even in minuscule amounts, it is a liquid state, not a solid. A gas does not technically have a mass. It is a vapor.
(You can find examples of the liquid state of window glass by closely examining old homes with the original glass panes. The bottoms will be noticeably and measurably thicker than the tops. They do move, but very slowly.)
Toothpaste is a very thick (or highly viscous) liquid. The distinctions get a little vague between these categories. But toothpaste is probably not quite firm enough to be considered a solid. ?unless it is frozen, of course. ?or perhaps very, very old.
...Toothpaste is a liquid because if you squirt it on a level surface it will spread out and not stay the same shape, after a while of course.
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