*ked-

in pathology, "collection of pus in some part of the body," 1610s, from Latin abscessus "an abscess" (the Latin word was used in a medical sense by Celsus), literally "a going away, departure," from the stem of abscedere "withdraw, depart, retire," from ab "off, away from" (see ab-) + cedere "to go, withdraw" (from PIE root *ked- "to go, yield"). The notion is that humors "go from" the body through the pus in the swelling.

"come to or arrive at" (a state, position, office, etc.), early 15c., from Latin accedere "approach, go to, come near, enter upon," from assimilated form of ad "to" (see ad-) + cedere "go, move, withdraw" (from PIE root *ked- "to go, yield"). Latin ad- usually became ac- before "k" sounds. Related: Acceded; acceding.