82 entries under expression topic. ×
| in disguise(idiom, concealment) | |
| in hiding(idiom, concealment) | |
| in holes and corners(idiom, hidden, fraudulent) | |
| in the shade(idiom, concealment) | |
| not expressed | |
| ohmic resistance | |
| railroad line | |
| railway line | |
| railway system | |
| revolutionary group | |
| sea bed | |
| sea bottom | |
| stream bed | |
| stream bottom | |
| subterranean space | |
| thermionic tube | |
| thermionic vacuum tube | |
| thermionic valve | |
| top secret(clandestine, undisclosed) | |
| truck bed |
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| APA | Smart Define. (2015). underground thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/underground/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "underground thesaurus" https://smartdefine.org/underground/thesaurus/synonyms (accessed September 21, 2026). |
| Harvard | Smart Define 2015, underground thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/underground/thesaurus/synonyms>. |
| MLA | Smart Define. "underground thesaurus" 3 November 2015. Web. 21 September 2026. <https://smartdefine.org/underground/thesaurus/synonyms> |