This is the 12773rd most frequent Swedish word.
stensäker
Absolutely certain; rock-solid sure.
Here, 'stensäker' is used metaphorically to mean 'absolutely certain'—displaying confidence without doubt.
Han var stensäker på att han hade rätt.
He was absolutely certain that he was right.
In this sentence, 'stensäker' conveys a certainty gained through experience or effort, emphasizing thorough learning.
Efter flera försök blev hon stensäker på hur uppgiften skulle lösas.
After several attempts, she became completely sure how the task should be solved.
Here, 'stensäker' implies reliability and solidity, connecting its literal sense of 'stone-like' to figurative meaning.