Longest word in English---"Floccinaucinihilipilification"

With 29 letters and 12 syllables, it is the longest non-technical word in the first edition of the Oxford English Dictionary (OED), which presents it as "enumerated in a well-known rule from the Eton Latin Grammar." The OED dates its first use in literature at 1741 in William Shenstone's Works in Prose and Verse: "I loved him for nothing so much as his flocci-nauci-nihili-pili-fication of money." In recent years, the word has been used in many scholarly articles in philosophy.

"Action or habit of estimating as worthless," 1741, a combination of four Latin words (flocci, nauci, nihili, pilifi) all signifying "at a small price" or "for nothing," which were listed together in a rule of the well-known Eton Latin Grammar. The kind of jocular formation that was possible among educated men in Britain in those days. Just so, as in praesenti, the opening words of mnemonic lines on conjugation in Lilley's 16c. Latin grammar, could stand alone as late as 19c. and be understood to 

mean "rudiments of Latin."