Longest Latin word?

[galen697]

What is the longest word in Latin (using the 1st principal part)? Off the top of my head, I'm thinking "obstupefacio", but I'm sure there are others that surpass this.

[adrianus]

15. circumcariphico (verb)
17. blandiloloquentulus (adj. smoothtalking) -> 24. blandiloloquentulissimus (very smooth talking) -> 26. blandiloloquentulissimorum (of the very smooth-talking ones)
17. fideicommissarius (n. or adj. will-executor)
17. struthiocamelinus (adj. of an ostrich)
17. quadringentesimus (ordinal 400th)
18 letters the following, however/ undeviginta autem litteras habet ità: undequinquagesimus (ordinal 49th)
19. duodequinquagesimus (ordinal 48th)
and 22. (if allowed/si licet) duodequadringentesimus (ordinal 398th)

[adrianus]

I forgot my favourite in English, which is an 18th-century, Latin-based joke word, and properly latin! It means the habit of estimating things as worthless. It certainly is still in use in English because I use it every chance I get. I'll now start in Latin!
Desiderium meum anglicè, jocosum saeculi decimi octavi è latino, ergô verbum latinum verum, oblitus sum! In usu continuat, quoniàm ego quidem, primo quoquè tempore, semper eo utor. Sic facere coepiam latiné!

28. floccinaucinihilipilificatio!! verbum latinum à "floccinaucinihilipilification" verbo anglico et jocoso, "actio seu mos rei ut vilis aestimandae" significans, quod ipsum à "flocci nauci nihili pili" latinis verbis derivatum est.

Ceterum censeo floccinaucinihilipilificationem esse delendam!

[galen697]

I forgot my favourite in English, which is an 18th-century, Latin-based joke word, and properly latin! It means the habit of estimating things as worthless. It certainly is still in use in English because I use it every chance I get. I'll now start in Latin!
Desiderium meum anglicè, jocosum saeculi decimi octavi è latino, ergô verbum latinum verum, oblitus sum! In usu continuat, quoniàm ego quidem, primo quoquè tempore, semper eo utor. Sic facere coepiam latiné!

28. floccinaucinihilipilificatio!! verbum latinum à "floccinaucinihilipilification" verbo anglico et jocoso, "actio seu mos rei ut vilis aestimandae" significans, quod ipsum à "flocci nauci nihili pili" latinis verbis derivatum est.

Ceterum censeo floccinaucinihilipilificationem esse delendam!

Catullus would certainly like that word. If only it would scan into hendecasyllabic!