What do we call a monument erected to the memory of the dead, with the body not present?

A monument erected to commemorate the dead without the presence of the body is referred to as a cenotaph. This term specifically denotes a structure that serves as a memorial, often built in honor of individuals who are interred elsewhere or whose remains cannot be located. Cenotaphs are frequently established in prominent public spaces or cemeteries to acknowledge the contributions or sacrifices of notable figures or loved ones.

The other terms mentioned do not accurately convey the same meaning. A grave marker typically denotes a physical marker placed at the site of an interment, indicating the presence of the deceased's remains. An epitaph is an inscription on a gravestone or plaque commemorating an individual, generally about their life or notable qualities. An elegy is a form of poetic expression, often reflecting on loss or mourning, rather than a physical structure dedicated to the deceased. Thus, cenotaph is the most precise term for a monument that commemorates someone when their body is not present.