From Longman Dictionary of Contemporary EnglishRelated topics: Agricultureperpendicularper‧pen‧dic‧u‧lar1 /ˌpɜːpənˈdɪkjələ◂ $ ˌpɜːrpənˈdɪkjələr◂/ adjective1VERTICALnot leaning to one side or the other but exactly vertical → vertical, horizontal
a perpendicular line
a perpendicular wall of rock2 →be perpendicular to something3 →Perpendicular —perpendicularly adverbExamples from the Corpusperpendicular• We make sure our horizontalstrokesprecede our perpendicular.• Ensure that the plumbline is perpendicular before you start to draw the line.• His eyes were deep set, his nosethin and perpendicular, his mouthnarrow and open.• The transmittedbeamconsists only of photons with the perpendicular polarisation.• a perpendicularpole• Looking over his left shoulder, he raises his arms perpendicular to his sides.• A1 and A2: carbon-bearing, electrolyte-saturated, measurementdirectionparallel and perpendicular to planes of foliation respectively.• The leaves are arranged so that each pair is situatedperpendicular to the axis of the preceding leaves.• Each of us spotted a different line of cobblesextending across the plain, perpendicular to the prevailinggradient of slope.• In a graph, the x-axis is perpendicular to the y-axis.• Behind them, there was a perpendicular wall of rock.• Looked a bitperpendicular when I saw it.PerpendicularPerpendicularAAin the style of 14th- and 15th-century English churches, which are decorated with straightupright lines →perpendicularRelated topics: Mathsperpendicularperpendicular2 noun [singular]VERTICALan exactly vertical position or lineOriginperpendicular1(1300-1400)Old Frenchperpendiculer, from Latin, from perpendiculum“plumb line”, from pendere“to hang”