One who insists on something unyieldingly: a stickler for neatness. (noun)
Something puzzling or difficult. (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.
Use "stickler" in a sentence
"The main stickler is that by the end of the book, the reader is left without a sense of closure."
"Now the only stickler is that it just so happens she’s out of town on business this week and doesn’t know she’s switching."
"Diane Groomes was known as a stickler for the rules City Desk"