IPA: /ɑːrˈkeɪnli/
KK: /ɑrˈkeɪnli/
In a way that is mysterious or known only to a few people.
The ancient texts were arcanely written, making them difficult to understand.
Arcanely is derived from "arcane" (from Latin "arcanus", meaning secret or hidden) and the adverbial suffix "-ly" (meaning in a manner of). The word "arcanely" means in a secretive or hidden manner.
Think of something that is 'hidden' ('arcanus') and how it is done 'in a manner' ('-ly'). This helps you remember that 'arcanely' refers to doing something in a secretive way.