Erectile dysfunction refers to the inadequate or absent erection of the penis when sexually aroused. However, it is only a disorder if the problems occur over a longer period of time (at least six months) and in more than two thirds of attempts. However, if erection problems occur from time to time, this is completely normal.
In colloquial language, erectile dysfunction is often referred to as impotence, although erectile dysfunction is only one form of impotence (impotentia coeundi) and the term can also refer to infertility (impotentia generandi).