unloyal
Prone to betrayal
Unloyal means not loyal—faithless or disloyal.
The word is less common than disloyal but carries the same meaning: He was unloyal to his friends when it mattered most.
Some consider it nonstandard, preferring disloyal, but unloyal appears in both speech and writing.
Disloyal and dangerous
- faithlessUntrustworthy, lacking loyalty
- traitorousGuilty of betrayal
- backstabbingCovert betrayal of trust
- two-facedInsincere and deceptive
unfaithful · perfidious · deceitful · double-crossing · turncoat · Judas · betrayer · snake
Betraying a partner's trust
- cheatingDeceptive rule-breaking
- adulterousUnfaithful to spouse
- inconstantProne to fluctuation
- fickleErratically disloyal in affection
straying · philandering · two-timing · uncommitted · wavering · unreliable · flighty · capricious
Disloyal to one's nation
- seditiousInciting rebellion against state
- mutinousDisposed to revolt
- rebelliousResisting authority or control
- defectingAbandoning a cause
unpatriotic · dissident · insurgent · subversive · turncoat · deserting · oath-breaking · collaborator
treacherous
Disloyal and dangerous
- faithlessUntrustworthy, lacking loyalty
- traitorousGuilty of betrayal
- backstabbingCovert betrayal of trust
two-faced · unfaithful · perfidious · deceitful · double-crossing · turncoat · Judas · betrayer · snake · sellout
unfaithful
Betraying a partner's trust
- cheatingDeceptive rule-breaking
- adulterousUnfaithful to spouse
- inconstantProne to fluctuation
fickle · straying · philandering · two-timing · uncommitted · wavering · unreliable · flighty · capricious · undevoted
treasonous
Disloyal to one's nation
- seditiousInciting rebellion against state
- mutinousDisposed to revolt
- rebelliousResisting authority or control
defecting · unpatriotic · dissident · insurgent · subversive · turncoat · deserting · oath-breaking · collaborator · quisling