Clueful, a rather unique word, is often used to describe someone who is knowledgeable, perceptive, or insightful. However, if you're looking for synonyms to avoid repetition or add variety to your language, several alternatives can be employed. Words such as astute, discerning, insightful, perspicacious, or shrewd can effectively convey the same meaning. These terms highlight a person's ability to comprehend and interpret situations, leaving no doubt about their meticulous observation or deep understanding. Hence, whether you're describing someone's intelligence, awareness, perceptiveness, or expertise, these synonyms for clueful are excellent choices to enhance your vocabulary and communication skills.