unfaithful -
not true to duty or obligation or promises; "an unfaithful lover"
faithful steadfast in affection or allegiance; "years of faithful service"; "faithful employees"; "we do not doubt that England has a faithful patriot in the Lord Chancellor"
inconstant likely to change frequently often without apparent or cogent reason; variable; "inconstant affections"; "an inconstant lover"; "swear not by...the inconstant moon"- Shakespeare
faithfulness,
fidelity accuracy with which an electronic system reproduces the sound or image of its input signal
apostate not faithful to religion or party or cause
perfidious,
punic,
treacherous tending to betray; especially having a treacherous character as attributed to the Carthaginians by the Romans; "Punic faith"; "the perfidious Judas"; "the fiercest and most treacherous of foes"; "treacherous intrigues"
unfaithful -
having sexual relations with someone other than your husband or wife, or your boyfriend or girlfriend; "her husband was unfaithful"
faithful steadfast in affection or allegiance; "years of faithful service"; "faithful employees"; "we do not doubt that England has a faithful patriot in the Lord Chancellor"
unfaithful -
not trustworthy; "an unfaithful reproduction"
unfaithful -
having the character of, or characteristic of, a traitor; "the faithless Benedict Arnold"; "a lying traitorous insurrectionist"
