Lying in or on, or pertaining to, the superficies or surface; not penetrating below the surface, literally or figuratively; being only on the surface; not reaching to the interior or essence; shallow: as, a superficial color; a superficial resemblance.Of persons or their mental states or acts, comprehending only what is apparent or obvious; not deep or profound; not thorough.In anatomy, not deep-seated or profound; lying on the surface of some part, or near but not on the surface of the whole body; subcutaneous; cutaneous: specifically said of various tissues and structures.Synonyms External, exterior, outer.Slight, smattering, shallow.