From BiblePortal Wikipedia

Vine's Expository Dictionary of NT Words [1]

A — 1: Ἀπολογία (Strong'S #627 — Noun Feminine — apologia — ap-ol-og-ee'-ah )

a speech made in defense. See Answer.

B — 1: Ἀπολογέομαι (Strong'S #626 — Verb — apologeomai — ap-ol-og-eh'-om-ahee )

See Answer , B, No. 4.

Webster's Dictionary [2]

(1): ( n.) That which defends or protects; anything employed to oppose attack, ward off violence or danger, or maintain security; a guard; a protection.

(2): ( n.) The act of defending, or the state of being defended; protection, as from violence or danger.

(3): ( n.) Prohibition; a prohibitory ordinance.

(4): ( n.) Act or skill in making defense; defensive plan or policy; practice in self defense, as in fencing, boxing, etc.

(5): ( n.) The defendant's answer or plea; an opposing or denial of the truth or validity of the plaintiff's or prosecutor's case; the method of proceeding adopted by the defendant to protect himself against the plaintiff's action.

(6): ( n.) Protecting plea; vindication; justification.

(7): ( n. & v. t.) See Defense.

Charles Buck Theological Dictionary [3]

See Self-Defence