arcane
Concise Oxford English Dictionary © 2008 Oxford University Press:
arcane /ɑːˈkeɪn/
▶adjective understood by few; mysterious.
– derivatives
arcanely adverb.
arcanely adverb.
– origin C16: from L. arcanus, from arcere ‘to shut up’, from arca ‘chest’.
'arcane' also found in these Oxford entries:

