Declensionist refers to a person who believes that their society, or a larger societal unit, is in decline. Some synonyms that can be used to describe a declensionist include pessimist, fatalist, and defeatist. The term "doomsayer" can also be used to describe someone who is a declensionist. Other synonyms include naysayer, cynic, and skeptic. These words describe a person who is very skeptical of any positive change or believes that nothing is ever going to change for the better. Ultimately, a declensionist is someone who sees only the negative aspects of their society, and is often labeled as a pessimist by those who believe in progress and forward-thinking ideas.