Longest Word in english

1.      Honorificabilitudinita - Tibus (27 letters)

2.      Antidisestablishmentarianism(28 letters)

3.      Floccinaucinihilipipification (29 letters)

4.      Supercalifragilisticeplalidocious (34 letters)

5.      Praetertranssubstantiationalistically (37 letters)

6.      Hepaticocholecystostcholecystenterostomy(40 letters)

7.      Pneumonoultramicroscopicsilicovolcanoconiosts (45 letters)

8.      Antipericatametaanaparcircumvolutiorectumgustpoops
of the coprofied (50 letters)

9.      Osseocarnisanguineoviscericartilagininervomedullary  
(51 letters)

10.  Aequeosalinocalcalinoceraceoaluminoscupreovitriolic 
(52 letters) 

11.  Bababadalgharaghtakamminapronnkonnbronntonnepronnt-
uonnthunntrovarrhounawnskawntoohoohoordeenenthurnuk  
(100 letters)

12.  Lopadotemachoselachogaleokranioleipsanodrimhypotrim-
matosilphiparaomelitokatakechymenokichlepikossyphophat-
toperisteralektryonoptekephalliokiglopeleiolagoiosiraiobaph-
etraganopterygon (182 letters)