What is going out on a limb?

in or into a dangerous or uncompromising position, where one is not joined or supported by anyone else; vulnerable.

Josh is a different type of person, he always does things and doesnt mind going out on a limb

going out on a limb - video

in or into a position where one is not joined or supported by anyone else.
a way of saying where one make him/herself isolated and takes a risk

I'm gonna go out on a limb and say that something's bothering you.

I wouldn't go out on a limb like this if I didn't have the data to justify it !

I am really going out on a limb supporting you with this, many people don't think it will work.