Merriam-Webster Collegiate Dictionary - internal

 adjective  Etymology: Middle English ~le, from Latin internus; akin to Latin inter between  Date: 15th century  1. existing or situated within the limits or surface of something: as  a.  (1) situated near the inside of the body  (2) situated on the side toward the median plane of the body  b. of, relating to, or occurring on the inside of an organized structure (as a club, company, or state) ~ affairs  2. relating or belonging to or existing within the mind  3. intrinsic, inherent ~ evidence of forgery in a document  4. present or arising within an organism or one of its parts ~ stimulus  5. applied or intended for application through the stomach by being swallowed an ~ remedy  • ~ity noun  • ~ly adverb