searching

Thorough.

Einstein's photoelectric equation has been subjected to very searching tests and it appears in every case to predict exactly the observed results.

Looking over closely; penetrating; severe.

a searching gaze; searching criticism

‘So you are going out there. Famous. Interesting too.’ He gave me a searching glance, and made another note.

Search; hunt.

Her songs take us through many mood changes from lighthearted lovesongs and social commentary to a serious searching for answers and understanding.

Depending on whom you ask, Antony Flew is either a true convert whose lifelong intellectual searchings finally brought him to God or a senescent scholar possibly being exploited by his associates.