Webster's 1828 Dictionary
ASSIDENT
a.[L. assideo, assidens, of ad and sedeo, to sit. ] Assident signs, in medicine, are such as usually attend a disease, but not always; distinguished from pathognomic signs, which are inseparable from it.
Webster's 1913 Dictionary
ASSIDENT
As "si *dent, a. Etym: [L. assidens, p. pr. of assid to sit by: cf. F.assident. See Assession. ] (Med. )
Defn: Usually attending a disease, but not always; as, assident signs, or symptoms.