a push
another effort; one more effort
「一押し」 has another reading with different meanings.
ドアが重くて、一押しした。
The door was heavy, so I gave it a push.
プロジェクトはあと一押しで完成する。
The project will be completed with just one more push.
先生のたった一押しで、彼は決心した。
With just one push from his teacher, he made up his mind.