Ineffectual is similar to ineffective, but while ineffective implies that something simply doesn't work, ineffectual carries with it the idea of weakness too.

Is there such a word as ineffectual?

not effectual; without satisfactory or decisive effect: an ineffectual remedy. unavailing; futile: His efforts to sell the house were ineffectual. powerless; impotent.

What does the ineffective mean?

1 : not producing an intended effect : ineffectual ineffective lighting. 2 : not capable of performing efficiently or as expected : incapable an ineffective executive.