资料来源 : Webster's Revised Unabridged Dictionary (1913)

Systemless \Sys"tem*less\, a.
   1. Being without system.

   2. (Nat. Hist.) Not agreeing with some artificial system of
      classification.

   3. (Biol.)Not having any of the distinct systems or types of
      structure, as the radiate, articulate, etc.,
      characteristic of organic nature; as, all unicellular
      organisms are systemless.