pernickety

UK: /pə^rˈnɪkəti/ US: (pər nik′i tē)

WordReference Random House Unabridged Dictionary of American English © 2021

per•nick•et•y  (pər nik′i tē), adj. 

1. Informal Terms persnickety.

• 1800–10; origin, originally Scots; of uncertain origin, originally; the prefix per- occurs in a number of other expressive words in Scots, e.g. pergaddus thump, clatter, perskeet fastidious, perjink trim, neat

per•nick′et•i•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

pernickety /pəˈnɪkɪtɪ/, US persnickety adj informal

1. excessively precise and attentive to detail; fussy
2. (of a task) requiring close attention; exacting

Etymology: 19th Century: originally Scottish, of unknown origin

WordReference Random House Learner's Dictionary of American English © 2021

per•snick•et•y /pɚˈsnɪkɪti/  also per•nick•e•ty /pɚˈnɪkɪti/   adj. [Informal.]

1. Informal Terms very fussy;
   paying too much attention to details:
   the persnickety English teacher who notices every comma that's in the wrong place.

WordReference Random House Unabridged Dictionary of American English © 2021

per•snick•et•y  (pər snik′i tē), adj. [Informal.]

1. Informal Terms overparticular;
   fussy.
2. Informal Terms snobbish or having the aloof attitude of a snob.
3. Informal Terms requiring painstaking care.

Also, pernickety. 

• origin, originally Scots, variant of pernickety 1885–90

per•snick′et•i•ness, n. 
Synonyms

• 1. . nitpicking, finicky.