adverb
attentively; cautiously; carefully
Describes doing something with careful attention, often to avoid mistakes or danger. Can imply both watchfulness and prudence.
彼は注意深く道路を渡った。
He crossed the road cautiously.
契約書を注意深く読んでください。
Please read the contract carefully.
Also means 'carefully' or 'prudently', but 注意深く emphasizes attentive observation, while 慎重に stresses cautious deliberation.
Formed from 注意 (attention, caution) + 深く (adverbial form of 深い, deep). Literally 'deeply attentive'.