Noun
an instrument of torture that is used to heat or crush the foot and leg
Source: WordNetFor Man's grim Justice goes its way, And will not swerve aside: It slays the weak, it slays the strong, It has a deadly stride: With iron heel it slays the strong, The monstrous parricide! Oscar Wilde
The trodden worms, which had so long writhed under the iron heel of the oppressor, were turning at last. The smouldering fire of discontent was shooting out tongues of flame here and there. The sore stricken, who had brooded in sullen anger over their wrongs, were rising to strike in their turn. Joseph Arch