noun
constant attendance; staying by someone's side
Often used for a doctor or nurse staying with a patient without leaving. Implies continuous, dedicated presence.
重病人には医者が付っ切りで看病した。
The doctor stayed constantly by the seriously ill patient's side to care for them.
母は熱を出した子供に付っ切りだった。
The mother was constantly attending to her feverish child.