ETYM Pref. dis- + loyal: cf. Old Fren. desloial, desleal, French déloyal. Related to Loyal.
Deserting one's allegiance or duty to leader or cause or principle.
Deliberately and abominably disloyal or likely to betray trust or confidence; SYN. traitorous, unfaithful.
ETYM Latin perfidious.
1. Guilty of perfidy; violating good faith or vows; false to trust or confidence reposed; teacherous; faithless.
2. Involving, or characterized by, perfidy.
1. Not true to duty or obligation or promises
2. Not trustworthy
Without loyalty; in a disloyal manner.
In a perfidious manner.
In an unfaithful undependable unreliable manner; SYN. undependably, unreliably.