Impotence

n. weakness, powerlessness, helplessness; inability to sustain an erection, inability to perform sexually (of a male)

Erectile dysfunction (ED or (male) impotence) is a sexual dysfunction characterized by the inability to develop or maintain an erection of the penis. There are various underlying causes, such as cardiovascular leakage and diabetes, many of which are medically treatable.The causes of erectile dysfunction may be physiological or psychological. Physiologically, erection is a hydraulic mechanism based upon blood entering and being retained in the penis, and there are various ways in which this can be impeded, most of which are amenable to treatment. Psychological impotence is where erection or penetration fails due to thoughts or feelings (psychological reasons) rather than physical impossibility; this can often be helped. Notably in psychological impotence there is a very strong placebo effect.
See more at Wikipedia.org...

Impotence, often called erectile dysfunction, is the inability to achieve or maintain an erection long enough to engage in [more]Impotence - Community and Resources

Noun
1. the quality of lacking strength or power; being weak and feeble
(synonym) powerlessness, impotency
(hypernym) quality
(hyponym) helplessness, weakness, impuissance
2. an inability (usually of a male) to copulate
(synonym) impotency
(hypernym) sterility, infertility
(hyponym) erectile dysfunction, male erecticle dysfunction, ED

n. impotence, infirmity