This is the 7400th most frequent Japanese word.
伸ばせ
"伸ばせ" means "stretch" or "extend" (command form).
Here, '伸ばせ' is used as an imperative form of the verb '伸ばす' indicating to stretch or extend something, in this case, the hand.
手を伸ばせば届きますよ。
If you stretch out your hand, you can reach it.
In this sentence, '伸ばせる' (potential form of '伸ばす') implies the ability to extend or broaden something, applied to dreams.
夢を伸ばせるように努力しています。
I am making efforts to extend my dreams.
Here, '伸ばせる' again refers to the potential form of '伸ばす,' meaning to let something grow or to make it longer, specific to hair.