faithful

Synonyms: affectionate allegiant ardent attached behind one circumspect confiding conscientious constant dependable devoted dutiful dyed-in-the-wool enduring fast firm genuine hard-core honest honorable incorruptible loving obedient on the level patriotic resolute scrupulous sincere staunch steadfast steady straight string along with sure tried tried and true true true-blue trustworthy trusty truthful unchanging unswerving unwavering upright veracious

Antonyms: dishonest disloyal false inconstant treacherous unfaithful unreliable untrue

Synonyms: close credible exact just lifelike precise right similar strict true trusty undistorted veracious veridical

Antonyms: different false inaccurate inexact uncertain