frag

frag \frag\ (fr[a^]g), v. t. [imp. & p. p. {fragged} (fr[a^]gd);
   p. pr. & vb. n. {fragging}.] [by shortening from
   fragmentation grenade; ca. 1965.] (Mil.)
   To assault, especially to kill or wound, with a fragmentation
   grenade. [Slang]

   Note: This term became popularized when disaffected American
         troops serving in Vietnam were reported on occasion to
         kill unpopular commanders by the use of grenades.
         [PJC]
    

frag
 n.,v.

   [from Vietnam-era U.S. military slang via the games Doom and Quake]

   1. To kill another player's {avatar} in a multiuser game. "I hold the
   office Quake record with 40 frags."

   2. To completely ruin something. "Forget that power supply, the
   lightning strike fragged it." See also {gib}.