priori
adj. C1 Advanced US //pɹaɪˈɔˌɹaɪ// pri·ori
adj. based on what you already know or believe, rather than on facts you have seen. It is often used in science or math to describe a belief before testing it.
adj. based on what is known or assumed before experience or observation. Often used in the phrase 'a priori' to describe reasoning that proceeds from general principles to specific instances.
The scientist had an a priori belief that the experiment would fail.
The researchers started with an a priori assumption that the new drug would be effective, but they needed data to confirm it.
In formal logic, an a priori argument is one that is considered valid regardless of empirical evidence, relying solely on the structure of the premises themselves.