What does "incompleteness" mean?

The state or condition of being not complete.

Incompleteness

Common synonyms include: absence, adulteration, beggary, broken thread, brokenness, defectibility.

noun

noun ·Uncommon ·College level

Noun

1
The state or condition of being not complete. uncountable, usually
"Its incompleteness in this respect makes the timetable of less value than some of its Continental counterparts, such as the French Horaires Mayeux; nevertheless, it is fair value at 5s."
2
the state of being crude and incomplete and imperfect wordnet

"The author calls attention to the incompleteness of that article."

From incomplete + -ness.