Definition of rottan in US English:

rottan

(also rotten, rottin)

noun

English Regional, Scottish, Northern
  • A rat.

Origin

Late 16th century; earliest use found in Edinburgh Testaments. Apparently a variant of ratton, with alteration of the vowel in the first syllable apparently after similar forms of rat.

Pronunciation

rottan

/ˈrɒt(ə)n/