[1] : The Collaborative International Dictionary of English v.0.48

generation \gen`era"tion\, n. oe. generacioun, f.
   g'en'eration, fr.l. generatio.
   1. the act of generating or begetting; procreation, as of
      animals.
      1913 webster

   2. origination by some process, mathematical, chemical, or
      vital; production; formation; as, the generation of
      sounds, of gases, of curves, etc.
      1913 webster

   3. that which is generated or brought forth; progeny;
      offspiring.
      1913 webster

   4. a single step or stage in the succession of natural
      descent; a rank or remove in genealogy. hence: the body of
      those who are of the same genealogical rank or remove from
      an ancestor; the mass of beings living at one period;
      also, the average lifetime of man, or the ordinary period
      of time at which one rank follows another, or father is
      succeeded by child, usually assumed to be one third of a
      century; an age.
      1913 webster

            this is the book of the generations of adam. --gen.
                                                  v. 1.
      1913 webster

            ye shall remain there in babylon many years, and
            for a long season, namely, seven generations.
                                                  --baruch vi.
                                                  3.
      1913 webster

            all generations and ages of the christian church.
                                                  --hooker.
      1913 webster

   5. race; kind; family; breed; stock.
      1913 webster

            thy mother's of my generation; what's she, if i be a
            dog?                                  --shak.
      1913 webster

   6. geom. the formation or production of any geometrical
      magnitude, as a line, a surface, a solid, by the motion,
      in accordance with a mathematical law, of a point or a
      magnitude; as, the generation of a line or curve by the
      motion of a point, of a surface by a line, a sphere by a
      semicircle, etc.
      1913 webster

   7. biol. the aggregate of the functions and phenomene which
      attend reproduction.
      1913 webster

   note: there are four modes of generation in the animal
         kingdom: scissiparity or by fissiparous generation,
         gemmiparity or by budding, germiparity or by germs, and
         oviparity or by ova.
         1913 webster

   alternate generation biol., alternation of sexual with
      asexual generation, in which the products of one process
      differ from those of the other, -- a form of reproduction
      common both to animal and vegetable organisms. in the
      simplest form, the organism arising from sexual generation
      produces offspiring unlike itself, agamogenetically.
      these, however, in time acquire reproductive organs, and
      from their impregnated germs the original parent form is
      reproduced. in more complicated cases, the first series of
      organisms produced agamogenetically may give rise to
      others by a like process, and these in turn to still other
      generations. ultimately, however, a generation is formed
      which develops sexual organs, and the original form is
      reproduced.

   spontaneous generation biol., the fancied production of
      living organisms without previously existing parents from
      inorganic matter, or from decomposing organic matter, a
      notion which at one time had many supporters; abiogenesis.
      1913 webster
see also:
alternate generation spontaneous generation 

[2] : The Collaborative International Dictionary of English v.0.48

spontaneous \sponta"neous\ spo^nt=a"n-eu^s, a. l.
   spontaneus, fr. sponte of free will, voluntarily.
   1. proceeding from natural feeling, temperament, or
      disposition, or from a native internal proneness,
      readiness, or tendency, without constraint; as, a
      spontaneous gift or proposition.
      1913 webster

   2. proceeding from, or acting by, internal impulse, energy,
      or natural law, without external force; as, spontaneous
      motion; spontaneous growth.
      1913 webster

   3. produced without being planted, or without human labor;
      as, a spontaneous growth of wood.
      1913 webster

   spontaneous combustion, combustion produced in a substance
      by the evolution of heat through the chemical action of
      its own elements; as, the spontaneous combustion of waste
      matter saturated with oil.

   spontaneous generation. biol. see under generation.
      1913 webster

   syn: voluntary; uncompelled; willing.

   usage: spontaneous, voluntary. what is voluntary is the
          result of a volition, or act of choice; it therefore
          implies some degree of consideration, and may be the
          result of mere reason without excited feeling. what is
          spontaneous springs wholly from feeling, or a sudden
          impulse which admits of no reflection; as, a
          spontaneous burst of applause. hence, the term is also
          applied to things inanimate when they are produced
          without the determinate purpose or care of man.
          "abstinence which is but voluntary fasting, and . . .
          exercise which is but voluntary labor." --j. seed.
          1913 webster

                spontaneous joys, where nature has its play,
                the soul adopts, and owns their firstborn away.
                                                  --goldsmith.
          1913 webster -- sponta"neously, adv. --
          sponta"neousness, n.
          1913 webster
see also:
spontaneous combustion spontaneous generation generation spontaneous voluntary sponta"neously 
sponta"neousness 

[3] : WordNet (r) 2.0

spontaneous generation
     n : a hypothetical organic phenomenon by which living organisms
         are created from nonliving matter syn: abiogenesis, autogenesis,
          autogeny
see also:
abiogenesis autogenesis autogeny 

Generation >> G Words
Generation, definition of term: Generation
generation_pag1.html

Spontaneous >> S Words
Spontaneous, definition of term: Spontaneous
spontaneous_pag1.html

Spontaneous Gen >> S Words
Spontaneous Gen, definition of term: Spontaneous Gen
spontaneous+gen_pag1.html

Spontaneous Com >> S Words
Spontaneous Com, definition of term: Spontaneous Com
spontaneous+com_pag1.html

Beat Generation >> B Words
Beat Generation, definition of term: Beat Generation
beat+generation_pag1.html