いたく

adverb

extremely; exceedingly; deeply

Used with verbs and adjectives to express a high degree; often found in literary or formal contexts.

• 彼かれの言こと葉ばにいたく感かん動どうした。

  I was deeply moved by his words.

• その知しらせを聞きいて、いたく驚おどろいた。

  I was extremely surprised to hear the news.

adverb

painfully

Only when written 痛く

Rare adverbial use of 痛い, meaning 'in a painful manner'; mostly seen in older or literary texts.

• 傷きずが痛いたくて眠ねむれなかった。

  The wound hurt so much I couldn't sleep.