based on custom rather than documentation; "an unwritten law"; "rites...so ancient that they well might have had their unwritten origins in Aurignacian times"- J.L.T.C.Spence
a stage in psychosexual development when the child's interest is concentrated in the mouth; fixation at this stage is said to result in dependence, selfishness, and aggression
of or involving the mouth or mouth region or the surface on which the mouth is located; "the oral cavity"; "the oral mucous membrane"; "the oral surface of a starfish"
using speech rather than writing; "an oral tradition"; "an oral agreement"
of or relating to or affecting or for use in the mouth; "oral hygiene"; "an oral thermometer"; "an oral vaccine"