The effects of electric and magnetic fields on magnetic and electric properties have been investigated for a triangular lattice antiferromagnet CuCrO(2) showing magnetically induced ferroelectric order. We demonstrate that ferroelectric polarization reversal can be finely tuned by using both magnetic and electric fields in the triangular lattice antiferromagnet. The observed magnetoelectric tunability can be attributed to small in-plane spin anisotropy and a resultant high degree of freedom for the direction of ferroelectric polarization, which is characteristic of a multiferroic triangular lattice antiferromagnet with out-of-plane 120 degrees spin structure.