unkindest
Least gentle treatment
Unkindest is the superlative form of unkind—the most cruel, harsh, or inconsiderate.
The word is best known from Shakespeare's the most unkindest cut of all, describing Brutus's betrayal of Caesar.
That famous line uses double superlative for emphasis, a construction no longer standard but preserved in the phrase.
Lacking pity or mercy
- mercilessShowing no clemency
- pitilessLacking any compassion
- callousCruelly insensitive to others
- ruthlessLacking any compassion
cold-blooded · inhumane · unfeeling · cold-hearted · hard-hearted · stony-hearted · uncompassionate · unsympathetic
Disloyal and dangerous
- backstabbingCovert betrayal of trust
- disloyalUntrue to commitments
- faithlessUntrustworthy, lacking loyalty
- falseNot matching reality
two-faced · deceitful · traitorous · perfidious · Brutus · Caesar · shocking · unexpected
Dividing via sharp edge
- bitingHarshly critical or cold
- causticChemically burning; bitterly mocking
- scathingSeverely and bitingly critical
- sharpFine-edged, or astute
blunt · stinging · piercing · wounding · barbed · acerbic · sardonic · derisive
Incapable of being pacified
- relentlessContinuing without pause
- unrelentingRefusing to let up
- unyieldingRefusing to give way
- inexorableImpossible to prevent
unbending · unsparing · remorseless · unpitying · unmerciful · stern · uncompromising · hard
heartless
Lacking pity or mercy
ruthless · cold-blooded · inhumane · unfeeling · cold-hearted · hard-hearted · stony-hearted · uncompassionate · unsympathetic · mean-spirited
treacherous
Disloyal and dangerous
- backstabbingCovert betrayal of trust
- disloyalUntrue to commitments
- faithlessUntrustworthy, lacking loyalty
false · two-faced · deceitful · traitorous · perfidious · Brutus · Caesar · shocking · unexpected · devastating
cutting
Dividing via sharp edge
- bitingHarshly critical or cold
- causticChemically burning; bitterly mocking
- scathingSeverely and bitingly critical
sharp · blunt · stinging · piercing · wounding · barbed · acerbic · sardonic · derisive · disparaging
implacable
Incapable of being pacified
- relentlessContinuing without pause
- unrelentingRefusing to let up
- unyieldingRefusing to give way
inexorable · unbending · unsparing · remorseless · unpitying · unmerciful · stern · uncompromising · hard · inflexible