Octuple refers to eightfold or eight times the amount, quantity, or number of something. Some antonyms for octuple include single, solitary, individual, one, alone, solo, sole, unique, and non-incremental. These words carry the opposite meaning of octuple as they refer to something that is singular, rather than multiple. Other antonyms for octuple may include words such as few, less, small, minor, or negligible, which indicate a reduction in quantity or size. Understanding antonyms can help in expanding one's vocabulary and providing more precise expressions when communicating.