Mnemonically refers to any device or technique used to aid in memory retention. There are several synonyms for mnemonically, including memorably, recollectively, and memorization-wise. Memorably implies something that is so impactful or unique that it's easily remembered. Recollectively means that something was remembered after an effort to recall it. Finally, memorization-wise is used to describe the manner in which things are remembered, and can include memory techniques such as repetition or visualization. No matter which synonym you use, the idea behind mnemonically remains the same--it's a tool to help make remembering things easier and more efficient.