Adverb
elsewhen (not comparable)
(archaic) At some other time or times; somewhen else.
And the multiverse concept first explored in Elsewhen gets very full treatment in Heinlein's last, World as Myth novels, particularly The Number of the Beast (1980), The Cat Who Walks Through Walls (1985) and To Sail Beyond the Sunset (1987). Source: Internet
"Elsewhen" suggests that the human mind is not bound to our here-and-now "slum of space-time" but can go voyaging into alternative timetracks of possibility. Source: Internet
Kurland's Perchance (1988), the first volume of the never-completed "Chronicles of Elsewhen", presents a multiverse of secretive cross-time societies that utilize a variety of means for cross-time travel, ranging from high-tech capsules to mutant powers. Source: Internet