Definition of "tickler" [tic•kler]

• One that tickles. (noun)
• A memorandum, book, or file to aid the memory. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The word tickler comes from the David Allen task management system which suggests a manual technique for maintaining a set of reminders and a habit of looking at them to see which are due."
• "RUBEL: I would recommend doing what lawyers do, which is keeping what we call a tickler file."
• "It turns out that the file a secretary keeps to remind her boss to do certain things at certain times is called a tickler file."