Internal /(?)/

In·tern·al

Internal

a.
  1. Inward; interior; being within any limit or surface; inclosed; -- opposed to external; as, the internal parts of a body, or of the earth.
  2. Derived from, or dependent on, the thing itself; inherent; as, the internal evidence of the divine origin of the Scriptures.
  3. Pertaining to its own affairs or interests; especially, (said of a country) domestic, as opposed to foreign; as, internal trade; internal troubles or war.
  4. Pertaining to the inner being or the heart; spiritual.
    With our Savior, internal purity is everything.
    — Paley.
  5. Intrinsic; inherent; real. [R.]
    The internal rectitude of our actions in the sight of God.
  6. Lying toward the mesial plane; mesial. (Anat.)

Phrases & Compounds
Internal angle
an interior angle. See under Interior.
Internal gear
a gear in which the teeth project inward from the rim instead of outward.