せいぜい精々seizei
1.
Used to express a sense of doing everything within one's ability, signifying a commitment to put forth maximum effort in an endeavor.
2.
Indicates an upper limit or maximum estimate, suggesting that the quantity or extent mentioned is the highest feasible under the circumstances.
3.
Conveys the idea of reaching an ultimate boundary in capability or availability, often implying that the situation is not likely to exceed that limit.
4.
Reflects a sense of modesty or realism about what can be achieved, often used to temper expectations.
Example:
桜の花は数日、せいぜい一週間しか持たない。