Mar 1, 2015
-"Ridelle Mystere", her full English name, is a play on "riddle" and "mystery", respectively. Her surname may also be a reference to "St. Mystere", the setting for the first game in the Professor Layton series. In addition, Dewey addresses her as "Miss Mystere", which may be a play on "missed mystery", in reference to her position as puzzle keeper.
-Her full French name, "Amy Stère", is a play on "a mystery". To make this even more obvious, she is also often referred to as "Miss Stère".
-Her full Spanish name, "Mysteria Enigma", is a play on "mysterious enigma" (an "engima" being something puzzling or mysterious).
-Her full Italian name, "Miss Terry", is another play on "mystery".
From Ridelle's AA wiki page. I love all her names