40 entries under thoroughly topic. ×

12
carefully(adverb, seriously, intensely, vigorously)
9
industriously(adverb, seriously, vigorously, closely)
8
assiduously(adverb, seriously, vigorously, closely)
7
strenuously(adverb, seriously, vigorously, closely)
6
painstakingly(adverb, seriously, vigorously, closely)
6
persistently(adverb, seriously, vigorously, closely)
6
doggedly(adverb, closely, meticulously, resolutely)
5
attentively(adverb, carefully, meticulously, faithfully)
5
faithfully(adverb, carefully, meticulously, resolutely)
5
hard(adverb, closely, carefully, meticulously)
5
heedfully(adverb, carefully, meticulously, faithfully)
5
intently(adverb, closely, carefully, faithfully)
5
meticulously(adverb, carefully, faithfully, fastidiously)
5
mindfully(adverb, carefully, faithfully, vigilantly)
4
thoughtfully(adverb, seriously, intensely, carefully)
4
untiringly(adverb, closely, meticulously, determinedly)
3
scrupulously(adverb, carefully, meticulously, faithfully)
3
unremittingly(adverb, seriously, vigorously, closely)
3
watchfully(adverb, carefully, meticulously, faithfully)
2
earnestly(adverb, vigorously, closely, actively)
<12>
11 years ago|4.9k views|share |citing 
APASmart Define. (2015). diligently thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/diligently/thesaurus/synonyms
ChicagoSmart Define. 2015. "diligently thesaurus" https://smartdefine.org/diligently/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2015, diligently thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/diligently/thesaurus/synonyms>.
MLASmart Define. "diligently thesaurus" 14 April 2015. Web. 27 September 2026. <https://smartdefine.org/diligently/thesaurus/synonyms>