Longest Latin word?

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.

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

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!

  1. 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!