2
alike(adjective, calm, direct, smooth, right)
2
bland(adjective, quiet, soft, gentle, flat)
2
continuous(adjective, calm, quiet, direct, smooth)
2
dead flat(expression, adjective, smooth, flat, even)
2
face down(verb, expression, adjective, phrasal verb, lying)
2
floor
2
horizontally
2
in line(expression, adjective, idiom, calm, smooth)
2
invariable(adjective, quiet, smooth, soft, gentle)
2
lying
2
matching(adjective, calm, direct, smooth, right)
2
planate(adjective, calm, quiet, direct, smooth)
2
reclining(adjective, smooth, low, level, lying)
2
rolled(adjective, calm, smooth, flat, plain)
2
stable(adjective, calm, quiet, direct, smooth)
2
steep(adjective, straight, upright, vertical)
2
straightforward(adjective, direct, smooth, right, solid)
2
unswerving(adjective, smooth, right, solid, level)
1
akin(adjective, calm, smooth, flat, plain)
1
alluvial
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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>