INTERNAL
In*tern"al, a. Etym: [L. internus; akin to interior. See Interior.]

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. Rogers.

6. (Anat.)

Defn: Lying toward the mesial plane; mesial. Internal angle (Geom.), an interior angle. See under Interior. — Internal gear (Mach.), a gear in which the teeth project inward from the rim instead of outward.

Syn.
— Inner; interior; inward; inland; inside.

INTERNAL-COMBUSTION; INTERNAL-COMBUSTION ENGINE
In*ter"nal-com*bus"tion, a. (Mach.)