343 entries under adjective topic. ×

5
rigorous
5
thoroughgoing(thorough, meticulous, painstaking)
5
vigorous(keen, energetic, lively, determined)
4
absorbed(complete, total, whole, attentive)
4
ambitious(work, energetic, daring, labour)
4
concentrated(strong, great, complete, sharp)
4
courageous(resolute, tenacious)
4
decisive(resolute, tenacious)
4
efficient(work, strain, firmness, labour)
4
engaged(keen, intense, energetic, lively)
4
enthusiastic(keen, intense, energetic, lively)
4
finical
4
hustling(energetic, active, daring, occupied)
4
in-depth
4
keen(strong, intense, energetic, powerful)
4
observing
4
persisting
4
persnickety(thorough, meticulous, fastidious, painstaking)
4
plodding(activity, work, labour, multitask)
4
reliable(certain, careful, resolute, thorough)
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APASmart Define. (2015). diligent thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/diligent/thesaurus/synonyms
ChicagoSmart Define. 2015. "diligent thesaurus" https://smartdefine.org/diligent/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, diligent thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/diligent/thesaurus/synonyms>.
MLASmart Define. "diligent thesaurus" 14 April 2015. Web. 23 September 2026. <https://smartdefine.org/diligent/thesaurus/synonyms>