the deep end
01
a situation that is very difficult because one is not prepared to deal with it
Idiom
Informal
例
I'm a little nervous about starting my graduate degree program, but I'm determined to jump in at the deep end and give it a go.
When I started my new job, they threw me in at the deep end by assigning me a major project on my first day.
02
the section of a swimming pool where the water is at its deepest point
