A terpolymer composition is described that contains a statistical amount of 50-98 wt % of a first repeating AA-BB comonomer unit; 1-25 wt % of a second repeating AA-BB comonomer unit; and 1-25 wt % of a repeating lactam comonomer unit or 1-25 wt % of a third repeating AA-BB comonomer unit, where the terpolymer composition exhibits a high melting point similar to that of PA66 while also exhibiting a significantly reduced crystallization rate and crystallization temperature.