1An adverb meaning 'at last' or 'finally', used when something happens after a long wait or difficulty.
長い会議がやっと終わった。
The long meeting finally ended.
三回目の挑戦で、試験にやっと合格した。
On my third attempt, I finally passed the exam.
やっと休日が来たので、ゆっくり休むつもりだ。
The holiday has finally arrived, so I plan to rest properly.
工事がやっと終わって、静かになった。
The construction work finally ended, and it became quiet.
2An adverb meaning 'barely' or 'just', indicating something was achieved only with difficulty or by a narrow margin.
駅まで走って、電車にやっと間に合った。
I ran to the station and just barely made the train in time.
給料日までやっと生活している。
I'm just barely getting by until payday.
先生の説明を聞いて、やっと意味が分かった。
After hearing the teacher's explanation, I finally (just barely) understood the meaning.