WordWeb Online

1. Belonging to a thing by its very nature
   "form was treated as something intrinsic, as the very essence of the thing";
   - intrinsical
    
2. (anatomy) situated within or belonging solely to the organ or body part on which it acts
   "intrinsic muscles"

See also: built-in, constitutional, essential, inalienable, inbuilt, inherent, inner, integral, internal, intimate, unalienable

Antonym: extrinsic

Encyclopedia: Intrinsic