A long shot

Meaning

An endeavor with a very low probability of success. It is used when you are attempting something difficult where the odds are stacked against you.

Realistic, cautious

Used in a sentence

• It is a long shot, but I am going to apply for the promotion anyway.
• Winning the lottery is a long shot, but someone has to win.
• I know it is a long shot, but do you think we can fix the engine before dinner?