IPA: /ɪn.kəmˈpliːt.li/
KK: /ɪnˈkəmˌpliːtli/
In a way that is not complete or finished.
The project was submitted incompletely, missing several important sections.
Incompletely → It is formed from "in-" (meaning not) and "complete" (from Latin "completus", meaning filled or finished) and "-ly" (a suffix used to form adverbs). The word "incompletely" means not fully filled or finished.
Think of 'not' ('in-') being added to 'complete' — this helps you remember that 'incompletely' means something is not fully finished.