Tickler
Pronunciation : Tic"kler
Part of Speech : n.
Definition : 1. One who, or that which, tickles.
2. Something puzzling or difficult.
3. A book containing a memorandum of notes and debts arranged in the order of their maturity. [Com. Cant, U.S.] Bartlett.
4. A prong used by coopers to extract bungs from casks. [Eng.]
Source : Webster's Unabridged Dictionary, 1913