declension (en)

(noun) a falling off or away; deterioration / (noun) descent slope

peremptory (en)

(adjective) putting an end to or precluding a right of action, debate, or delay / (adjective) not providing an opportunity to show cause why one should not comply / (adjective) admitting of no contradiction / (adjective) expressive of urgency or command / (adjective) characterized by often imperious or arrogant self-assurance / (adjective) indicative of a peremptory attitude or nature; haughty / (noun) a challenge (as of a juror) made as of right without assigning any cause

plashing (en)

(verb) to cause a splashing or spattering effect / (verb) to break the surface of (water); splash

tenebrous (en)

(adjective) shut off from the light; dark murky / (adjective) hard to understand; obscure / (adjective) causing gloom