check up on chec·ku·pon uncommon verb 1. examine so as to determine accuracy, quality, or condition “check the brakes” “Check out the engine” Synonymscheckcheck up onlook intocheck outsuss outcheck overgo overcheck into Related words Word family checkoutcheckchecker Broader terms analyze Narrower terms watch Related verbs check WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.