29 entries under density topic. ×

16
impenetrable(adjective, close, hard, tough, solid)
10
compact(adjective, close, set, hard, tough)
7
close(adjective, set, hard, tough, solid)
7
dense(adjective, set, hard, tough, firm)
7
thick(adjective, close, set, hard, tough)
6
nonporous(adjective, hard, solid, rigid, resistant)
4
concrete(hard, solid, rigid)
4
hard(adjective, set, tough, firm, solid)
3
solid(adjective, close, set, hard, tough)
3
substantial(adjective, close, set, hard, tough)
2
constipated
2
imporous
2
massive
2
serried
2
thickset
1
coherent
1
cohesive
1
crystalline
1
gnarled
1
incompressible(adjective, firm)
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APASmart Define. (2015). impermeable thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/impermeable/thesaurus/synonyms
ChicagoSmart Define. 2015. "impermeable thesaurus" https://smartdefine.org/impermeable/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, impermeable thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/impermeable/thesaurus/synonyms>.
MLASmart Define. "impermeable thesaurus" 14 April 2015. Web. 22 September 2026. <https://smartdefine.org/impermeable/thesaurus/synonyms>