pernickety

Pernickety appeared in Scottish English around 1808, meaning excessively particular or fastidious about small details. Its origin is uncertain. Some scholars connect it to the Scots word pernicky or pernick, meaning fussy, but the deeper root is lost. The word sounds like what it means—the clipped, precise consonants mirror the behavior it describes.

Scottish emigrants brought pernickety to North America in the mid-19th century. Somewhere in the Atlantic crossing, the word gained an extra 's'—Americans began saying persnickety. The variant first appeared in American print around 1892. No one has satisfactorily explained the insertion. Perhaps American mouths wanted more sibilance; perhaps the 's' just felt right.

Both forms coexisted for decades. British English kept pernickety; American English preferred persnickety. The divide is one of the many small transatlantic spelling differences that separate the two dialects—like colour/color or aluminium/aluminum, except this one has no logical basis. It is pure caprice.

Today, persnickety is slightly old-fashioned in American English—a word your grandmother might use—while pernickety remains current in British English. Both describe the same behavior: an obsessive attention to small things that most people consider unimportant. The word is its own best example.