4
observing(adjective, attentive)
4
persisting(adjective, persevering)
4
persnickety(adjective, thorough, meticulous, fastidious, painstaking)
4
plodding(adjective, activity, work, labour, multitask)
4
reliable(adjective, certain, careful, resolute, thorough)
4
resolved(adjective, resolute)
4
unfaltering
4
vigilant(adjective, attentive, vigilant)
3
unflinching(adjective, resolute)
3
committed(adjective, work, strain, firmness, resolute)
3
deliberate(adjective, resolute)
3
elaborate(adjective, precise, thorough, meticulous)
3
exact(adjective, thorough, meticulous, painstaking)
3
plugging(adjective, persevering)
3
priggish(adjective, precise, thorough, meticulous, fastidious)
3
productive(adjective, work, strain, firmness, labour)
3
punctual(adjective, thorough, meticulous, painstaking)
3
serious(adjective, thoughtful, resolute, practical, controlled)
3
severe(adjective, strong, powerful, penetrating, fastidious)
3
sharp(adjective, strong, powerful, attentive, penetrating)
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APASmart Define. (2015). diligent thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/diligent/thesaurus/synonyms
ChicagoSmart Define. 2015. "diligent thesaurus" https://smartdefine.org/diligent/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, diligent thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/diligent/thesaurus/synonyms>.
MLASmart Define. "diligent thesaurus" 14 April 2015. Web. 21 September 2026. <https://smartdefine.org/diligent/thesaurus/synonyms>