This is the 15680th most frequent Russian word.
принципиальным
"Principled" or "fundamental."
In this sentence, 'принципиальным' denotes someone demonstrating strong adherence to certain principles or moral codes.
Он был принципиальным в своих решениях.
He was principled in his decisions.
Here, 'принципиальным' describes the individual's characteristic of upholding integrity and ethical standards despite opportunities for personal gain.
Будучи принципиальным человеком, он не принял предложение взятки.
Being a principled person, he declined the bribery offer.
In this context, 'принципиальным' emphasizes how critical the timely completion of the project was as a matter of principle.