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

  1  definition  found 
 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
 
  Axis  \Ax"is\,  n.;  pl  {Axes}.  [L.  axis  axis,  axle.  See  {Axle}.] 
  A  straight  line  real  or  imaginary,  passing  through  a  body, 
  on  which  it  revolves,  or  may  be  supposed  to  revolve;  a  line 
  passing  through  a  body  or  system  around  which  the  parts  are 
  symmetrically  arranged. 
 
  2.  (Math.)  A  straight  line  with  respect  to  which  the 
  different  parts  of  a  magnitude  are  symmetrically  arranged; 
  as  the  axis  of  a  cylinder,  i.  e.,  the  axis  of  a  cone, 
  that  is  the  straight  line  joining  the  vertex  and  the 
  center  of  the  base;  the  axis  of  a  circle,  any  straight 
  line  passing  through  the  center. 
 
  3.  (Bot.)  The  stem;  the  central  part  or  longitudinal 
  support,  on  which  organs  or  parts  are  arranged;  the 
  central  line  of  any  body.  --Gray. 
 
  4.  (Anat.) 
  a  The  second  vertebra  of  the  neck,  or  {vertebra 
  dentata}. 
  b  Also  used  of  the  body  only  of  the  vertebra,  which  is 
  prolonged  anteriorly  within  the  foramen  of  the  first 
  vertebra  or  atlas,  so  as  to  form  the  odontoid  process 
  or  peg  which  serves  as  a  pivot  for  the  atlas  and  head 
  to  turn  upon 
 
  5.  (Crystallog.)  One  of  several  imaginary  lines,  assumed  in 
  describing  the  position  of  the  planes  by  which  a  crystal 
  is  bounded. 
 
  6.  (Fine  Arts)  The  primary  or  secondary  central  line  of  any 
  design. 
 
  {Anticlinal  axis}  (Geol.),  a  line  or  ridge  from  which  the 
  strata  slope  downward  on  the  two  opposite  sides. 
 
  {Synclinal  axis},  a  line  from  which  the  strata  slope  upward 
  in  opposite  directions,  so  as  to  form  a  valley. 
 
  {Axis  cylinder}  (Anat.),  the  neuraxis  or  essential,  central 
  substance  of  a  nerve  fiber;  --  called  also  {axis  band}, 
  {axial  fiber},  and  {cylinder  axis}. 
 
  {Axis  in  peritrochio},  the  wheel  and  axle,  one  of  the 
  mechanical  powers. 
 
  {Axis  of  a  curve}  (Geom.),  a  straight  line  which  bisects  a 
  system  of  parallel  chords  of  a  curve;  called  a  {principal 
  axis},  when  cutting  them  at  right  angles,  in  which  case  it 
  divides  the  curve  into  two  symmetrical  portions,  as  in  the 
  parabola,  which  has  one  such  axis,  the  ellipse,  which  has 
  two  or  the  circle,  which  has  an  infinite  number.  The  two 
  axes  of  the  ellipse  are  the  {major  axis}  and  the  {minor 
  axis},  and  the  two  axes  of  the  hyperbola  are  the 
  {transverse  axis}  and  the  {conjugate  axis}. 
 
  {Axis  of  a  lens},  the  straight  line  passing  through  its 
  center  and  perpendicular  to  its  surfaces. 
 
  {Axis  of  a}  {telescope  or  microscope},  the  straight  line  with 
  which  coincide  the  axes  of  the  several  lenses  which 
  compose  it 
 
  {Axes  of  co["o]rdinates  in  a  plane},  two  straight  lines 
  intersecting  each  other  to  which  points  are  referred  for 
  the  purpose  of  determining  their  relative  position:  they 
  are  either  rectangular  or  oblique. 
 
  {Axes  of  co["o]rdinates  in  space},  the  three  straight  lines 
  in  which  the  co["o]rdinate  planes  intersect  each  other 
 
  {Axis  of  a  balance},  that  line  about  which  it  turns. 
 
  {Axis  of  oscillation},  of  a  pendulum,  a  right  line  passing 
  through  the  center  about  which  it  vibrates,  and 
  perpendicular  to  the  plane  of  vibration. 
 
  {Axis  of  polarization},  the  central  line  around  which  the 
  prismatic  rings  or  curves  are  arranged.  --Brewster. 
 
  {Axis  of  revolution}  (Descriptive  Geom.),  a  straight  line 
  about  which  some  line  or  plane  is  revolved,  so  that  the 
  several  points  of  the  line  or  plane  shall  describe  circles 
  with  their  centers  in  the  fixed  line  and  their  planes 
  perpendicular  to  it  the  line  describing  a  surface  of 
  revolution,  and  the  plane  a  solid  of  revolution. 
 
  {Axis  of  symmetry}  (Geom.),  any  line  in  a  plane  figure  which 
  divides  the  figure  into  two  such  parts  that  one  part  when 
  folded  over  along  the  axis,  shall  coincide  with  the  other 
  part 
 
  {Axis  of  the}  {equator,  ecliptic,  horizon}  (or  other  circle 
  considered  with  reference  to  the  sphere  on  which  it  lies), 
  the  diameter  of  the  sphere  which  is  perpendicular  to  the 
  plane  of  the  circle.  --Hutton. 
 
  {Axis  of  the  Ionic  capital}  (Arch.),  a  line  passing 
  perpendicularly  through  the  middle  of  the  eye  of  the 
  volute. 
 
  {Neutral  axis}  (Mech.),  the  line  of  demarcation  between  the 
  horizontal  elastic  forces  of  tension  and  compression, 
  exerted  by  the  fibers  in  any  cross  section  of  a  girder. 
 
  {Optic  axis  of  a  crystal},  the  direction  in  which  a  ray  of 
  transmitted  light  suffers  no  double  refraction.  All 
  crystals,  not  of  the  isometric  system,  are  either  uniaxial 
  or  biaxial. 
 
  {Optic  axis},  {Visual  axis}  (Opt.),  the  straight  line  passing 
  through  the  center  of  the  pupil,  and  perpendicular  to  the 
  surface  of  the  eye. 
 
  {Radical  axis  of  two  circles}  (Geom.),  the  straight  line 
  perpendicular  to  the  line  joining  their  centers  and  such 
  that  the  tangents  from  any  point  of  it  to  the  two  circles 
  shall  be  equal  to  each  other 
 
  {Spiral  axis}  (Arch.),  the  axis  of  a  twisted  column  drawn 
  spirally  in  order  to  trace  the  circumvolutions  without 
 
  {Axis  of  abscissas}  and  {Axis  of  ordinates}.  See  {Abscissa}. 

Recent Content

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Shared content with implied attribution.