Excogitation

[Sarah]

The act of excogitating; a devising in the thoughts; invention;contrivance.

[Julene]

thinking something out carefully as to achieve complete [comprehension] of it;
[conception], invention;
Excogitation means the act of thinking or studying intensely,
and hence the result of thinking; a contrivance.
Excogitation is from excogitate
to think out; devise; study intensely,
derived ultimately from Latin excogitare.
It is first found in English in the early [sixteenth] century.