Fetching details from the dictionary...

at the most; at best
to the utmost; as much as possible; as much as one can
この部屋には精精五人しか入れない。
This room can hold five people at most.
今月は精精三回しか運動できなかった。
I only managed to exercise three times at most this month.
予算は精精十万円くらいだろう。
The budget is probably around 100,000 yen at best.