Source : WordNet®

fall through
     v : fail utterly; collapse; "The project foundered" [syn: {fall
         flat}, {founder}, {flop}]

Source : Free On-Line Dictionary of Computing

fall through
     
         (The American misspelling "fall thru" is
        also common)
     
        1. To exit a loop by exhaustion, i.e. by having fulfilled its
        exit condition rather than via a break or exception condition
        that exits from the middle of it.  This usage appears to be
        *really* old, dating from the 1940s and 1950s.
     
        2. To fail a test that would have passed control to a
        subroutine or some other distant portion of code.
     
        3. In C, "fall-through" occurs when the flow of execution in a
        {switch statement} reaches a "case" label other than by
        jumping there from the switch header, passing a point where
        one would normally expect to find a "break".  A trivial
        example:
     
        	switch (colour)
        	{
        	case GREEN:
        	  do_green();
        	  break;
        	case PINK:
        	  do_pink();
        	  /* FALL THROUGH */
        	case RED:
        	  do_red();
        	  break;
        	default:
        	  do_blue();
        	  break;
        	}
     
        The effect of the above code is to "do_green()" when colour is
        "GREEN", "do_red()" when colour is "RED", "do_blue()" on any
        other colour other than "PINK", and (and this is the important
        part) "do_pink()" *and then* "do_red()" when colour is "PINK".
        Fall-through is {considered harmful} by some, though there are
        contexts (such as the coding of state machines) in which it is
        natural; it is generally considered good practice to include a
        comment highlighting the fall-through where one would normally
        expect a break.  See also {Duff's Device}.