Achievement

[Sarah]

An escutcheon or ensign armorial; now generally applied to thefuneral shield commonly called hatchment. Cussans.

[Jason Yan]

A thing done successfully with effort, skill, or courage.

[Kai]

[Achievements] are synonymous with [Gamerscore] on the Xbox 360.
When you unlock an Achievement, you get Gamerscore. To unlock an Achievement, you need to fulfil a specific task.
Achievements vary in difficulty to unlock; some take little to no effort whatsoever, whereas some are [nigh] impossible to achieve.

[Renato]

countable a thing that someone has done successfully, especially using their own effort and skill
the greatest scientific [achievement] of the decade
It was a remarkable achievement for such a young player.
They were proud of their childrens achievements.
[AWL] Collocations
[uncountable] the act or process of achieving something
the need to raise standards of achievement in education
Even a small success gives you a sense of achievement (= a feeling of pride).

[Tina]

Successfully [reaching] [OG] during a sexual [act].

[Sonia]

something very good and difficult that you have succeeded in doing: