Besides ultrasound detection, hearing a fetal heartbeat is definite proof of pregnancy. (pregnancy-baby.com)
Alfred senses that his wife may be cheating on him but has not definite proof. (seligfilmnews.com)
not easily convinced; skeptical until shown definite proof... - Excerpted from Webster's New World Dictionary (1970 edition) As in medicine, theology names a whole field by one... (religion-online.org)