61 entries under extra topic. ×

7
substitute(noun, cover, reserve, alternative)
5
alternate(cover, supply, reserve, replacement)
5
backup(noun, adjective, increase, reserve)
5
replacement(noun, adjective, spare, reserve)
5
reserve(noun, adjective, increase, substitute)
4
auxiliary(noun, adjective, increase, spare, supply)
3
emergency(noun, adjective, increase, spare, reserve)
3
second(substitute, replacement, auxiliary, supernumerary)
3
spare(noun, adjective, reserve, replacement)
3
supplemental(adjective, increase, auxiliary, supernumerary)
3
supplementary(adjective, increase, auxiliary, supernumerary)
2
ancillary(adjective, substitute, auxiliary, supernumerary)
2
supernumerary(adjective, substitute, replacement, temporary)
2
surrogate(noun, supply, agent, substitute)
2
temporary(noun, reserve, substitute, replacement)
1
additional(adjective, spare, replacement, temporary)
1
artificial(adjective, auxiliary, supernumerary)
1
dummy(supply, agent, replacement, alternate)
1
makeshift(supply, agent, replacement, alternate)
1
odd(adjective, replacement)
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APASmart Define. (2015). standby thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/standby/thesaurus/synonyms
ChicagoSmart Define. 2015. "standby thesaurus" https://smartdefine.org/standby/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, standby thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/standby/thesaurus/synonyms>.
MLASmart Define. "standby thesaurus" 13 April 2015. Web. 22 September 2026. <https://smartdefine.org/standby/thesaurus/synonyms>