The Collaborative International Dictionary
iron out differences
Iron \I"ron\, v. t. [imp. & p. p. Ironed; p. pr. & vb. n. Ironing.]
To smooth with an instrument of iron; especially, to smooth, as cloth, with a heated flatiron; -- sometimes used with out.
To shackle with irons; to fetter or handcuff. ``Ironed like a malefactor.''
--Sir W. Scott.-
To furnish or arm with iron; as, to iron a wagon.
iron out differences resolve differences; settle a dispute.