Lexicon

A B C D E F G H I J K L M N O P Q R S T U V
Rec Ref
Reco Recr

Recondite

adjective

(of a subject or knowledge) little known; abstruse: the book is full of recondite information.

[Craig Mod, in a blog post]

Recrudescence

n. (formal)

  1. The recurrence of an undesirable condition

[Beowulf — Trans. Maria Dahvana Headley]