severe / intense, acute, extreme / violent

goblin, ghost; an apparition

change in society, climate, or condition, transformation, variety / variation / declension / (sumo) a step to one side during the tachiai, the initial charge at the start of a sumo match; a sidestep

to change, to vary

(meteorology) climate

(grammar) declension

undergo a chemical change

chemical reaction, chemical change

climate change

climatology