* μνήμη (mnēmē): This is probably the closest single word. It refers to memory, the faculty of remembering, and also the thing remembered. It's a broader term than "remembrance," encompassing both the act and the content of remembering.
* ανάμνησις (anamnēsis): This word implies a *recalling* or *recollection* of something from the past, often something significant or meaningful. It carries a stronger sense of conscious effort to remember than *mnēmē*. It's closer to the active process of remembrance.
* μνημόσυνον (mnēmosynon): This word refers to a memorial or commemoration, often a ceremony or act of remembrance. It's less about the act of remembering in the individual and more about the public act of remembering someone or something.
Therefore, the best Greek word for "remembrance" depends on context. If you're talking about the general faculty of remembering, *mnēmē* is best. If you mean the act of actively recalling something, *anamnēsis* is more appropriate. And if you're referring to a memorial or commemorative act, *mnēmosynon* fits.