Fetching details from the dictionary...
earnestly; immediately; exactly
ひたひたばしり走りに走っはしって間に合わまにあわせた。
I ran without stopping and made it in time.
ひたひたかくし隠しにしていた秘密ひみつがばれた。
The secret I'd been hiding was found out.
彼女かのじょはひたすら勉強べんきょうに打ち込んうちこんだ。
She devoted herself entirely to studying.