having no doubt or knowing exactly that something is true, or known to be true, correct, exact, or effective
I am certain that zebras have stripes.
She felt a certain unease about the upcoming changes in her life.
The detective had a certain suspicion about the identity of the culprit.
After the interview, he had a certain confidence that he would get the job.
The novel had a certain charm that captivated readers from the very first page.
