prefix
Prefix that intensifies the following verb, adding a sense of doing something single-mindedly, directly, or with full concentration. Common in words like ひたすら, ひた隠す, ひた走る.
彼はひたすらに努力を続けた。
He continued his efforts single-mindedly.
犯人はひた隠しに隠したが、すぐに見つかった。
The culprit tried to hide it completely, but it was found immediately.
The prefix ひた is of native Japanese origin, likely related to the idea of 'direct' or 'straight'. The exact derivation is uncertain.