2  definitions  found 
 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
 
  Allotropism  \Al*lot"ro*pism\,  Allotropy  \Al*lot"ro*py\,  n.  [Gr. 
  ?  other  +  direction,  way  ?  to  turn:  cf  F.  allotropie.] 
  (Chem.) 
  The  property  of  existing  in  two  or  more  conditions  which  are 
  distinct  in  their  physical  or  chemical  relations. 
 
  Note:  Thus  carbon  occurs  crystallized  in  octahedrons  and 
  other  related  forms,  in  a  state  of  extreme  hardness,  in 
  the  diamond;  it  occurs  in  hexagonal  forms,  and  of 
  little  hardness,  in  black  lead;  and  again  occurs  in  a 
  third  form  with  entire  softness,  in  lampblack  and 
  charcoal.  In  some  cases,  one  of  these  is  peculiarly  an 
  active  state,  and  the  other  a  passive  one  Thus  ozone 
  is  an  active  state  of  oxygen,  and  is  distinct  from 
  ordinary  oxygen,  which  is  the  element  in  its  passive 
  state. 
 
  From  WordNet  r  1.6  [wn]: 
 
  allotropism 
  n  :  the  phenomenon  of  an  element  existing  in  two  or  more 
  physical  forms  [syn:  {allotropy}] 

browse words by letter
a b c d e f g h i j k l m n o p q r s t u v w x y z
or search   thesauri dictionary search words