What's the adjective for slanderousness? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs slander and slandre which may be used as adjectives within certain contexts.
“In course it air ter yer credit ye kin be ez good ez ter keep yer hands off'n the critter when he air so aboosive to yer face an' so slandersome ter yer back.”