Leaving no stone unturned is a popular idiom often used to describe thorough and exhaustive efforts made in a particular task or aim. Antonyms for this phrase could range from being hasty and careless, to being lackadaisical and negligent in approach. Some antonyms for leaving no stone unturned could include careless, slapdash, slipshod, lackadaisical, cursory, half-hearted, unwilling, and inattentive. On the other hand, those who put in the effort to leave no stone unturned could be described by antonyms such as dispersive, inattentive, cursory, and perfunctory. Ultimately, leaving no stone unturned is a phrase that emphasizes the importance of being thorough in every task, while neglecting such efforts could result in unsatisfactory results.