faultlessly is a form of:

Faultless



adjective
1.
(without fault) ដែលគ្មានទោស, គ្មានសេចក្ដីឆ្គាំឆ្គង, ដែលសុក្រិត, ភាពមិនគ្រប់លក្ខណ៍, ដែលគ្មានសេចក្ដីខ្វះ, ដែលឥតខ្ចោះ, ដែលគ្រប់លក្ខណ៍, លេញ, ដែលបរិបូរ, ដែលគ្មានកំហុស
ENGLISH MEANING
adjective
1.
Without fault; not defective or imperfect; free from blemish; free from incorrectness, vice, or offense; perfect; as, a faultless poem.
1.
complete, entire, full, utter, whole
2.
blameless, holy, perfect, pure, sinless
3.
consummate, excellent, ideal, superlative
4.
absolute, downright, unqualified, utter, ant, deficient, incomplete, lacking
1.
deficient, incomplete, lacking