adjective

showing or having an insensitive and cruel disregard for others.

his callous comments about the murder made me shiver

heartless,unfeeling,uncaring,cold,cold-hearted,hard,as hard as nails,hard-hearted,with a heart of stone,stony-hearted,insensitive,lacking compassion,hard-bitten,cold-blooded,hardened,case-hardened,harsh,cruel,ruthless,brutal,unsympathetic,uncharitable,indifferent,unconcerned,unsusceptible,insensible,bloodless,soulless,hard-boiled,indurate,indurated,marble-hearted

noun

variant spelling of callus.