I. per ‧ pen ‧ dic ‧ u ‧ lar 1 /ˌpɜːpənˈdɪkjələ◂, ˌpɜːpənˈdɪkjʊlə◂ $ ˌpɜːrpənˈdɪkjələr◂/ BrE AmE adjective
[ Date: 1300-1400 ; Language: Old French ; Origin: perpendiculer , from Latin , from perpendiculum 'plumb line' , from pendere 'to hang' ]
1 . not leaning to one side or the other but exactly vertical ⇨ vertical , horizontal :
a perpendicular line
a perpendicular wall of rock
2 . be perpendicular to something if one line is perpendicular to another line, they form an angle of 90 degrees SYN at right angles to :
a road perpendicular to the highway
3 . Perpendicular in the style of 14th- and 15th-century English churches, which are decorated with straight upright lines
—perpendicularly adverb
II. perpendicular 2 BrE AmE noun [singular]
an exactly vertical position or line