hardhearted (adj.)

• brazen
• callous
• calloused
• case-hardened
• cold
• coldhearted
• conscienceless
• flinty
• hard
• hard-boiled
• hardened
• heartless
• impervious
• insensitive
• inured
• obdurate
• pachydermatous
• seared
• shameless
• steely
• stony
• stonyhearted
• thick-skinned
• unblushing
• uncompassionate
• unemotional
• unfeeling
• unmerciful
• unnatural
• unresponsive
• unsympathetic