/ ˈstɪklə(r); NAmE / noun
stickler (for sth) a person who thinks that a particular quality or type of behaviour is very important and expects other people to think and behave in the same way :
a stickler for punctuality
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WORD ORIGIN
mid 16th cent. (in the sense umpire ): from obsolete stickle be umpire , alteration of obsolete stightle to control , frequentative of Old English stiht(i)an set in order .