Probationer, n. Novice.
Probe, v. a. Prove, test, verify, investigate, scrutinize, examine, search, sound, explore, sift, look into.
Probity, n. Integrity, uprightness, honesty, worth, rectitude, virtue, goodness, righteousness, trustworthiness, trustiness, principle, sincerity, truthfulness, veracity, honor, conscientiousness, justice, equity, fairness, incorruptibility, soundness.
Problem, n. Question (to be solved), enigma, puzzle, riddle, moot point, point in dispute, point to be solved or settled, question at issue, vexed question.