事后的想法（名词）

(noun) An object, comment, idea or explanation added after the original statement or plan.

EXAMPLE: A large swimming pool was added to the hotel as an afterthought, and unfortunately it was placed in an inconvenient location on the resort property.

这家酒店后来添设了一个大的游泳池，可惜它在度假酒店里的位置不好。

ballpark figure

大概的数字

An acceptable and reasonable estimate. (NOTE: a “ballpark” is an enclosed field or stadium for playing the American game of baseball)

EXAMPLE: At this early stage of planning, I don't need the exact cost of the new project, but just a ballpark figure will be quite helpful.

在规划的早期，我不必知道新项目的精确成本，有一个大概的数字就会很有帮助。