Source : Webster's Revised Unabridged Dictionary (1913)

Firm \Firm\, a. [Compar. {Firmer}; superl. {Firmest}.] [OE.
   ferme, F. ferme, fr.L. firmus; cf. Skr. dharman support, law,
   order, dh? to hold fast, carry. Cf. {Farm}, {Throne}.]
   1. Fixed; hence, closely compressed; compact; substantial;
      hard; solid; -- applied to the matter of bodies; as, firm
      flesh; firm muscles, firm wood.

   2. Not easily excited or disturbed; unchanging in purpose;
      fixed; steady; constant; stable; unshaken; not easily
      changed in feelings or will; strong; as, a firm believer;
      a firm friend; a firm adherent.

            Under spread ensigns, moving nigh, in slow But firm
            battalion.                            --Milton.

            By one man's firm obediency fully tried. --Milton.

   3. Solid; -- opposed to fluid; as, firm land.

   4. Indicating firmness; as, a firm tread; a firm countenance.

   Syn: Compact; dense; hard; solid; stanch; robust; strong;
        sturdly; fixed; steady; resolute; constant.