High up; aloft — indicating physical height or being held high (somewhat literary/old-fashioned usage).
旗が高々と掲げられ、式典が始まった。
A flag was raised high and the ceremony began.
子どもはおもちゃを高々と持ち上げて見せた。
The child held the toy up high to show it.
カイトは空高々と舞っている。
The kite is flying high in the sky.
At most; only; merely — used to indicate an upper limit or to downplay a quantity (similar to 'at best' or 'only').
この仕事はたかだか二、三時間で終わるだろう。
This job will probably finish in at most two or three hours.
彼の貢献はたかだか数回の助言にすぎない。
His contribution was merely a few pieces of advice at best.
たかだか五千円程度の違いで決める必要はない。
There's no need to decide over a difference of at most five thousand yen.