Adam Clarke on Acts 22:1

Men, brethren, and fathers - A Hebrew form of expression for brethren and fathers: for two classes only are addressed. See the note on Act 7:2.

Hear ye my defense - Μου της απολογιας, This apology of mine; in this sense the word apology was anciently understood: hence the Apologies of the primitive fathers, i.e. their defenses of the Christian religion. And this is as proper literal meaning; but it is now used only as implying an excuse for improper conduct. That this is an abuse of the term requires no proof.