Wiktionary
check up on
vb. To examine or inspect something in order to determine its condition; to check out
WordNet
check up on
v. examine so as to determine accuracy, quality, or condition; "check the brakes"; "Check out the engine" [syn: check, look into, check out, suss out, check over, go over, check into]
Usage examples of "check up on".
In fact, she didn't like anyone who had the power to come in here and check up on her.
But anybody could have hired him to check up on you, on some pretext or other.
Fernack said ponderously, "I had to check up on the other guests in the hotel.
What with being so busy with reports, I've not had a chance to check up on my advisors, and make sure that they're handling their duties properly.