long shot
noun
1- a venture or guess that has only the slightest chance of succeeding or being accurate成功率极低的尝试; 轻率的冒险; 碰运气的事; 瞎猜：
it's a long shot, but well worth trying.
这是碰运气的事, 不过很值得一试。
1.1
- (not) by a long shot informal (not) by far or at all〈非正式〉根本（没有）：
she had not told Rory everything, not by a long shot.
她没把所有的事告诉罗里, 根本没有。