A sleuth is someone who investigates mysteries or crimes, searching carefully for clues to solve puzzles that others can't figure out. The word originally meant a bloodhound used for tracking, but now it describes human detectives (both real and fictional) who follow trails of evidence.

Famous sleuths from books include Sherlock Holmes, who notices tiny details that reveal the truth, and Nancy Drew, who solves mysteries through careful observation and clever thinking. Real-life sleuths work as private investigators or police detectives, interviewing witnesses, examining crime scenes, and piecing together what happened.

You can sleuth something out by investigating it carefully. If your lunch keeps disappearing from your backpack, you might sleuth out the mystery by looking for crumbs, questioning suspects, and watching for suspicious behavior. Good sleuthing requires patience, attention to detail, and the ability to see patterns others miss.

Whether tracking down a lost library book or figuring out who ate the last cookie, sleuthing means sticking with the search until you discover the truth.