Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
scintilla, iota, jot, smidgin (nn.)
All these mean “an infinitesimally small bit,” and all are clichés. Jot is a spelling pronunciation of a late medieval spelling of iota (jota), the name of the smallest letter in the Greek alphabet. Smidgin may come from a dialectal word, smitch, meaning “a tiny smudge” and hence “a very small bit.” And scintilla means “a spark” in Latin; the singular is almost the only form we ever use, although it has two plurals: scintillas and, very rarely, scintillae.
