French

Adjective

consciencieux m ‎(feminine singular consciencieuse, masculine plural consciencieux, feminine plural consciencieuses)

1. conscientious, thorough

References

1. ↑ “conscientious”, in OED Online, Oxford: Oxford University Press, launched 2000.
2. ↑ “consciencieux” in le Trésor de la langue française informatisé (The Digitized Treasury of the French Language).