We don't have synonyms for chelys yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are chely, chelas and chels.
(N) :
The chelys or chelus (both meaning "turtle" or "tortoise"), was a stringed musical instrument, the common lyre of the ancient Greeks, which had a convex back of tortoiseshell or of wood shaped like the shell.
(N) :
The chelys or chelus (both meaning "turtle" or "tortoise"), was a stringed musical instrument, the common lyre of the ancient Greeks, which had a convex back of tortoiseshell or of wood shaped like the shell.