English
elseness
From else + -ness.
Formed from else + -ness
Proto-Indo-European *h₂el- ‘other’
…
Proto-Germanic *aljas ‘of another’
Proto-West Germanic *alljas ‘else’
Old English elles ‘other’
Middle English ells
English else
Today it means
noun The quality of being something else.
Language periods are conventional ranges, not dates for this word.
Etymograph / elseness