Medical Dictionary senescent adjective se·nes·cent \ si-ˈnes-ᵊnt \ Trending Now: More Trending: lowlife kakistocracy slimeball salacious oligarch SEE ALL See What's Trending Now See More Trending Words What's Trending Now More Trending Words lowlife 'a person of low moral character' kakistocracy 'government by the worst people' slimeball 'a morally repulsive or odious person' salacious 'arousing or appealing to sexual desire' oligarch 'government in which a small group exercises control' SEE ALL medical Definition of senescent : relating to, characterized by, or associated with senescence senescent persons senescent arthritis Learn More about senescent See words that rhyme with senescent Thesaurus: All synonyms and antonyms for senescent Seen and Heard What made you want to look up senescent? Please tell us where you read or heard it (including the quote, if possible). show hide