v. 1. To stay near; watch and care for. The nurse was told to sit by the patient until he woke up. Mother sat by her sick baby all night. 2. To sit and watch or rest especially while others work. Don't just sit idly by while the other children are all busy.
SIT BY
Meaning of SIT BY in English
American idioms English vocabulary. Английский словарь американских идиом. 2012