76 entries under smooth topic. ×

24
level(noun, adjective, quiet, direct)
20
flat(adjective, calm, quiet, direct)
16
even(adjective, adverb, calm, quiet)
15
plane(noun, adjective, calm, quiet, direct)
11
recumbent(adjective, flat, low, level)
10
prone(adjective, low, level, down)
10
straight(adjective, calm, direct, right)
9
flush(adjective, calm, quiet, direct)
9
prostrate(adjective, low, level, down)
8
direct(adjective, right, flat, solid)
7
supine(adjective, low, level, down)
6
decumbent(adjective, low, level, down)
6
true(adjective, direct, right, flat)
6
unbroken(adjective, calm, quiet, direct)
6
uniform(adjective, calm, quiet, right)
6
uninterrupted(adjective, calm, quiet, direct)
5
regular(adjective, calm, quiet, right)
4
right(adjective, direct, flat, solid)
4
parallel(adjective, calm, direct, right)
4
plain(adjective, calm, quiet, soft)
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APASmart Define. (2015). horizontal thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/horizontal/thesaurus/synonyms
ChicagoSmart Define. 2015. "horizontal thesaurus" https://smartdefine.org/horizontal/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, horizontal thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/horizontal/thesaurus/synonyms>.
MLASmart Define. "horizontal thesaurus" 10 April 2015. Web. 22 September 2026. <https://smartdefine.org/horizontal/thesaurus/synonyms>