Other forms: looked after; looking after; looks after
To look after someone is to keep an eye on or watch them. Many parents count on their oldest children to look after their younger siblings.
If you promise to look after your best friend's cat, it's your responsibility to make sure the cat is safely inside at night and has plenty to eat and drink. When nurses look after a patient in the hospital, they watch for dangerous symptoms and keep the patient comfortable. This "watch out for" or "take care of" meaning has been used since the late fourteenth century.