24
vertical(noun, adjective, smooth, sharp, solid)
20
erect(verb, adjective, smooth, sharp, solid)
17
steep(adjective, sharp, course, extreme, straight)
17
upright(noun, adjective, adverb, smooth, solid)
16
plumb(adjective, smooth, solid, short, straight)
14
straight(adjective, direct, right, level, straight)
13
orthogonal(adjective, verticality, perpendicularity)
11
sheer(adjective, smooth, sharp, solid, level)
7
precipitous(adjective, smooth, sharp, solid, level)
6
normal(adjective, verticality)
6
horizontal(adjective, rectilinear)
6
up-and-down(adjective, upright, variable, steep, vertical)
5
standing(verb, adjective, firm, straight, upright)
5
abrupt(adjective, sharp, course, quick, upright)
5
stand-up(adjective, straight, upright, erect, vertical)
4
even(adverb, rectilinear)
4
rectangular(verticality, perpendicularity)
4
upstanding(adjective, firm, straight, upright, erect)
3
diagonal
3
right
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APASmart Define. (2015). perpendicular thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/perpendicular/thesaurus/synonyms
ChicagoSmart Define. 2015. "perpendicular thesaurus" https://smartdefine.org/perpendicular/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, perpendicular thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/perpendicular/thesaurus/synonyms>.
MLASmart Define. "perpendicular thesaurus" 13 April 2015. Web. 22 September 2026. <https://smartdefine.org/perpendicular/thesaurus/synonyms>