1) French word used in English 2) Unhealthy 1) Unhealthy 
of, like or pertaining to dental cavities; decayed
• (a.) Affected with caries; decaying; as, a carious tooth.
Relating to or affected with caries. ... (05 Mar 2000) ... 
(kar´e-әs) affected with or of the nature of caries.
Ca'ri·ous adjective [ Latin cariosus , from caries dacay.] Affected with caries; decaying; as, a carious tooth. 
Type: Term Pronunciation: kār′ē-ŭs Definitions: 1. Relating to or affected with caries.
[adj] - (of teeth) affected with cavities or decay
carious (KAYR ee uhs) 1. Affected with or pertaining to caries. 2. Having pits or perforations.
adjective (of teeth) affected with cavities or decay