This is the 1096th most frequent Polish word.
niespełna
"Nearly," "just under," or "less than."
Here, 'niespełna' is used to mean 'less than', indicating the limited amount of time available.
Nie miałem niespełna godzinę, aby dokończyć projekt.
I had less than an hour to complete the project.
'Niespełna' here functions as 'less than', describing the weight as slightly below one kilogram.
Ta książka waży niespełna kilogram.
This book weighs less than a kilogram.
In this sentence, 'niespełna' implies 'lack of', connecting to the concept of insufficient reasoning.