1. verb To check the status, condition, or wellbeing of someone or something through an inspection or visit. We need to check up on grandma and see how she is coping with all this snow. I just checked up on the baby, and he's still sleeping. Can you check up on the dryer and tell me if it's still running?

2. noun A visit to a doctor for an examination, often as part of routine monitoring (rather than for an acute condition or reason). In this usage, the phrase is often hyphenated. Oh, it's just my yearly check-up, nothing to worry about.