IPA: /ˈtʃɛkʌp/
KK: /ˈtʃɛkˌʌp/
A routine medical examination to check a person's health.
I have a checkup scheduled with my doctor next week.
Checkup → It is formed from "check" (from Old French *eschequier*, meaning to inspect or verify) and "up" (meaning to a higher position or state). The word "checkup" refers to an inspection or examination to ensure everything is in good condition or health.
Think of 'checking' something to make sure it is in good condition and 'up' meaning to ensure it is at its best.
No commonly confused words.