conscientious

UK: /ˌkɒnʃiˈɛnʃəs/

US: /ˌkɑnʃiˈɛnʃəs/

US: (kon′shē en′shəs, kon′sē-)

WordReference Random House Learner's Dictionary of American English © 2026

con•sci•en•tious /ˌkɑnʃiˈɛnʃəs/   adj. 

1. very careful;
   thorough;
   painstaking:
   She was a conscientious student who always did her work.
2. acting according to conscience;
   fair:
   a conscientious judge.

con•sci•en•tious•ly, adv.: 

conscientiously working on the book.

con•sci•en•tious•ness, n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2026

con•sci•en•tious  (kon′shē en′shəs, kon′sē-), adj. 

1. controlled by or done according to conscience;
   scrupulous:
   a conscientious judge.
2. meticulous;
   careful;
   painstaking;
   particular:
   conscientious application to the work at hand.

• Medieval Latin conscientiōsus, equivalent. to Latin conscienti(a) conscience + -ōsus -ous
• 1605–15

con′sci•en′tious•ly, adv. 
con′sci•en′tious•ness, n. 
Synonyms

• 1. just, upright, honest, faithful, devoted, dedicated.
• 2. See painstaking. 

Collins Concise English Dictionary © HarperCollins Publishers::

conscientious / ˌkɒnʃɪˈɛnʃəs/ adjective

1. involving or taking great care; painstaking; diligent
2. governed by or done according to conscience

ˌconsciˈentiously adverb

ˌconsciˈentiousness noun