What's the noun for sententiousness? Here's the word you're looking for.
sentence
(obsolete) Sense; meaning; significance.
(obsolete) One's opinion; manner of thinking. [14th-17th c.]
(now rare) A pronounced opinion or judgment on a given question. [from 14th c.]
(dated) The decision or judgement of a jury or court; a verdict. [from 14th c.]
The judicial order for a punishment to be imposed on a person convicted of a crime. [from 14th c.]
A punishment imposed on a person convicted of a crime.
(obsolete) A saying, especially form a great person; a maxim, an apophthegm. [14th-19th c.]
(grammar) A grammatically complete series of words consisting of a subject and predicate, even if one or the other is implied, and typically beginning with a capital letter and ending with a full stop. [from 15th c.]