In algebra, what does the curvy sideways "m" symbol mean?

It means "is an element of". If you have a set named S and S = { 1, 3, 2 }. Then the "elements" or "members" of S are 1, 2, and 3.

In symbols: 1 ∈ S, 2 ∈ S, and 3 ∈ S.

It is called epsilom, lower-case in this situation. It has many meanings depending on its context.

However, the most common use and meaning of epsilom in math is a very very very very small number.

does it look like this? Ɛ. If it is this, it's just epsilon, which denotes a small quantity, as something, such as a function approach a limit. but this is calculus stuff. Otherwise it's much easier to just ask your teacher.

∈

so 3,4,5 ∈ x
means that 3,4,5 is in the set x

look up the words element, or set

there's more to it, but i'm really distracted right now ;)

ξ
slice/push ratio = (speed parallel to cutting edge/speed perpendicular to the cutting edge)

Curvy M usually means measurement.
Example: M=13 in or M of <a = 2


Or something like that.

google it