2  definitions  found 
 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
 
  Sinus  \Si"nus\,  n.;  pl  L.  {Sinus},  E.  {Sinuses}.  [L.,  a  bent 
  surface,  a  curve,  the  folds  or  bosom  of  a  garment,  etc.,  a 
  bay.  Cf  {Sine},  n.] 
  1.  An  opening;  a  hollow;  a  bending. 
 
  2.  A  bay  of  the  sea;  a  recess  in  the  shore. 
 
  3.  (Anat.  &  Zo["o]l.)  A  cavity;  a  depression.  Specifically: 
  a  A  cavity  in  a  bone  or  other  part  either  closed  or 
  with  a  narrow  opening. 
  b  A  dilated  vessel  or  canal. 
 
  4.  (Med.)  A  narrow,  elongated  cavity,  in  which  pus  is 
  collected;  an  elongated  abscess  with  only  a  small  orifice. 
 
  5.  (Bot.)  A  depression  between  adjoining  lobes. 
 
  Note:  A  sinus  may  be  rounded,  as  in  the  leaf  of  the  white 
  oak,  or  acute,  as  in  that  of  the  red  maple. 
 
  {Pallial  sinus}.  (Zo["o]l.)  See  under  {Pallial}. 
 
  {Sinus  venosus}.  [L.,  venous  dilatation.]  (Anat.) 
  a  The  main  part  of  the  cavity  of  the  right  auricle  of 
  the  heart  in  the  higher  vertebrates. 
  b  In  the  lower  vertebrates,  a  distinct  chamber  of  the 
  heart  formed  by  the  union  of  the  large  systematic 
  veins  and  opening  into  the  auricle. 
 
  From  WordNet  r  1.6  [wn]: 
 
  sinus 
  n  1:  an  abnormal  passage  leading  from  a  suppurating  cavity  to  the 
  body  surface  [syn:  {fistula}] 
  2:  any  of  various  air-filled  cavities  especially  in  the  bones 
  of  the  skull 
  3:  a  wide  channel  containing  blood;  does  not  have  the  coating 
  of  an  ordinary  blood  vessel  [syn:  {venous  sinus}] 

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