adverb taking the 'to' particle
eagerly waiting; impatiently waiting
Describes the state of waiting with great anticipation or impatience, often used with verbs like 待つ. The repetition intensifies the feeling.
彼は今か今かと彼女の返事を待っている。
He is waiting eagerly for her reply.
子どもたちは今か今かとプレゼントが開けられるのを待っていた。
The children were waiting impatiently to open their presents.