I. ˌpər-pən-ˈdi-kyə-lər adjective
Etymology: Middle English perpendiculer, from Middle French, from Latin perpendicularis, from perpendiculum plumb line, from per- + pendēre to hang — more at pendant
Date: 14th century
1.
a. : standing at right angles to the plane of the horizon : exactly upright
b. : being at right angles to a given line or plane
2. : extremely steep : precipitous
3. often capitalized : of or relating to a medieval English Gothic style of architecture in which vertical lines predominate
4. : relating to, uniting, or consisting of individuals of dissimilar type or on different levels
Synonyms: see vertical
• per·pen·dic·u·lar·i·ty -ˌdi-kyə-ˈla-rə-tē noun
• per·pen·dic·u·lar·ly -ˈdi-kyə-lər-lē adverb
II. noun
Date: 1571
: a line at right angles to a line or plane (as of the horizon)