pissintunicus

Vulgar Latin *pīssi(āre) (“to piss”) +‎ in (“in, inside”) +‎ tunic(a) (“tunic”) +‎ -us (2^nd-declension noun suffix).

• (modern Italianate Ecclesiastical) IPA^(key): [pis.sin̪ˈt̪uː.ni.kus]

pīssintunicus m (genitive pīssintunicī); second declension

1. (Medieval Latin, derogatory, very rare) tunic-pisser
   • c. 1288, Salimbene di Adam, “De domino Nicholao Regino episcopo [About the bishop sir Niccolò from Reggio]”, in Cronica [Chronicle]‎^[1]; republished as Ferdinando Bernini, editor, volume 1, Bari: Gius[eppe] Laterza & sons, 1942, page 54:

     Dixit igitur michi pater meus: ‛Fili dilecte, non credas istis pissintunicis’ — id est qui in tunicis mingunt —, ‛qui te deceperunt, sed veni mecum, et omnia mea tibi dabo’.

     Then my father said to me: "Beloved son, do not believe these tunic-pissers (meaning "those who urinate inside the tunics"), who deceived you; come with me instead, and I will give you all I have."

Second-declension noun.