>The one that grinds my gears is "bottoms up" instead of "bottom up."
Why does that "grind your gears?"
The term "bottoms up" is (unless I'm missing something important -- am I?) just the plural of "bottom up."
And given that the phrase is an admonition to drink what's in your container (hence seeing the bottom of the glass pointing up), it's usually (although I suppose it could be more prevalent when drinking alone, but I guess we'll never know) offered among a group (two or more) of folks, making "bottoms up" appropriate as it refers to more than one "bottom."
Again, I could be missing something important here. If so, please enlighten me.