Pen Drawing w/ Color Pencil [1998] The act or an instance of hindering, obstructing, or impeding. Something that hinders, obstructs, or impedes. Physics The variation of wave amplitude that occurs when waves of the same or different frequency come together. Electronics The inhibition or prevention of clear reception of broadcast signals. The distorted portion of a received signal. The negative or distorting effect that new learning can have on previous learning or that previous learning can have on new learning.